iPhone 4 review: Apple's latest is much more than an upgrade

In 2007, the iPhone was truly revolutionary and everyone was just grateful to have them at all. Every June since, there’s been a new model. Apple typically kept adding features like 3G, GPS, the ability to run third-party apps ... features that seemed thrilling and exotic within the context of the iPhone but which in the larger world of smartphones were about as unusual as nitrogen molecules in the atmosphere.

But who cares? Each of these features made the iPhone materially better. And the true star of the iPhone experience was always the iPhone OS (now iOS 4), which I’m convinced remains head-and-shoulders the easiest, most attractive, and most meticulously-cultivated mobile OS out there.

Another June has come, and we inevitably have another iPhone. As I run through the list of the iPhone 4’s new features, I am once again tempted to crank up my cynicism generator and note that most these items are features we’ve seen before on other phones: things like a high-definition display, an LED flash, a forward-facing camera and the ability to do video conferencing.

If a quick glance at the iPhone 4’s new features inspires initial cynicism, spending five days immersed in the actual device makes another impression entirely. For the first time since 2007, I feel as though the device I’m carrying isn’t merely an improved iPhone, but a truly new one.

iPhone 4 Design

I’m surprised by what often passes for mobile phone design these days. I flip a $200 phone in my hands in search of the Power button and it feels like a 1984 handheld electronic football game. It’s filled with odd angles and bumps, and I can feel loose seams where sections of the case don’t fit together properly.

The iPhone 4 feels as though someone sat down, cracked his or her knuckles, and decided that they were going to design and construct the hell out of this thing.

The iPhone 4 is a frame of stainless steel that contains the phone’s screen and electronics, sandwiched between two sheets of aluminosilicate glass, at the back and the front. The frame is interrupted sparingly and politely by the usual small assortment of iPhone function buttons, done up in brushed metal. At 9.3 millimeters thin, the iPhone is the thinnest smartphone on the market, according to Apple.

Well, I can’t imagine a phone being any thinner without sacrificing function. I was concerned that the flat shape and hard edges would be uncomfortable to hold and operate. Not so; the iPhone 4 feels terrific in your hand. It has a positive and reassuring heft as you root it out of a jacket pocket. That kind of thing actually does matter.

Another advantage of this design is that its thin profile and straight, simple lines make it more “case-able” than any other iPhone. In some ways, it seems like a “blank” phone. You can add protection to the iPhone without necessarily adding bulk and ugliness ... two factors which have historically led me to carry my various phones around as-is, naked and afraid.

Apple has started the ball rolling with their own “bumper” cases: a rubberized collar (available in six colors) that snaps around the stainless-steel frame and offers a welcome measure of impact-protection.

At $29, the bumper seems a bit pricey. But it isn’t just a thick rubber band: the iPhone’s power and volume buttons are covered by well-engineered mechanical pushers. Once it’s in place, the bumper looks like an integral part of the iPhone.

I like what the bumper does to the iPhone 4. It adds practically no bulk to the phone and doesn’t mar its clean design at all. Meanwhile, its rubberized surface makes the iPhone much “grippier” and prevents it from sliding away from you on a marble tabletop when you make a clumsy reach for it.

Which brings us to the subject of ...

Durability

The iPhone 4 represents a radical new design. I’ve never seen a phone that even comes close to this.

Which naturally invited me to wonder about how durable this design is. Once, while juggling car keys and packages, I dropped a Nexus One about 40 inches straight onto a marble floor. The dent and the scuff proved that it had landed right on a corner of the case. The impact had sent the battery and the battery cover flying but otherwise, the phone was completely undamaged.

And that’s what I’ve come to expect from plastic cases. I trust them. All I know about stainless steel is that it transmits force instead of absorbing it; what I know about glass is that it fractures instead of patiently rippling.

In my briefings with Apple, I was told a little bit about this aluminosilicate glass. It’s actually 30 times stronger than ordinary plastic and it’s even used in the windshields of military helicopters.

Fab. But what happens to a military helicopter if it slips out of your coat pocket and drops onto your driveway as you’re getting out of the car? I’ve never done that to any of my own military helicopters, so I really have no idea.

All of these things were on my mind as I unboxed the iPhone 4 and charged it up.

Before I tell you what happened to this phone, I should point out that my brother tech columnist Walt Mossberg over at the Wall Street Journal dropped his prerelease iPhone 4 “several times from a few feet onto a hard surface with no problem.” Ed Baig over at USA Today said that “an Apple executive dropped it in front of me. The phone was undamaged.”

BoingBoing “banged it on the side of metal tables” without incident.

I mention all of this intentional abuse of Apple property for two reasons:

First, to indicate that the iPhone 4 is indeed designed to be very tough, and in particular, that if Apple was willing drop one in front of a reviewer, then they must be pretty confident about the iPhone 4’s durability.

And secondly, to make myself feel a little better about the fact that I accidentally dropped and broke Apple's loaner iPhone 4 about 10 hours after unboxing it (see the accompanying gallery).

Yeah. I’m not proud about that. The back panel was thoroughly cracked up ... though the iPhone still worked fine.

I was out with friends, it was after dinner, and I was idly playing with the iPhone 4 on top of the table the same way I idly play with my iPhone 3GS and my Nexus One. But for some reason, it skidded out of my reach and clattered onto the hard floor.

It wasn’t in a bumper case. If it were, I probably couldn’t have fumbled it across the table and it might have had some protection when it hit the hard floor. I couldn’t tell if it had hit the metal table leg on the way down or had smacked into the floor cleanly. But the results were pretty impeccable.

So: what have we learned, Charlie Brown?

Actually, not very much. I don’t think it’s reasonable to expect any consumer phone to survive a drop from a table. As soon as a phone becomes airborne, it’s out of warranty and enters the realm of “Do you feel lucky today, punk?”

The experience did encourage me to spend a lot of time over the past five days investigating the durability of the iPhone 4. This YouTube video is typical of what I’ve been hearing and seeing:

It’s a static drop test in which the iPhone 4 free-falls from what appears to be about forty inches, straight onto asphalt. It’s perfectly fine after the first drop. The guy in the video has to drop it four times to get the screen to break. It’s clear that he’s even trying to impart some spin after the first one.

This, and conversations with other iPhone 4 users, has left me convinced that the iPhone 4 is (at the very least) no less durable than any other consumer smartphone, despite its radical new design. You don’t need to handle it with anything more than the usual amount of caution and care you’d use with any smartphone.

I'm annoyed that the iPhone now has two crackable glass panels instead of one. But it appears that any drop that would break an iPhone 4 would have totaled an iPhone 3GS just as readily. The lesson remains: take care of your toys.

That said: I’ll definitely be carrying my iPhone — and all of my phones — in cases from now on.

I asked Apple if the Apple Stores offered a specific repair for a broken back panel.

Obviously, it was carelessly-inflicted damage and shouldn’t be covered by warranty. But I’ve seen the iPhone 4 disassembled: it would appear that the back panel lifts straight off after the removal of two exposed screws.

Apple referred me to the standard policy regarding out-of-warranty repairs: it’s a flat-rate fee of $199. I suspect that replacement rear panels will soon become popular items on fix-your-iPhone-yourself retail sites.

Signal Issues

I noticed something odd with the iPhone from almost the moment I first powered it up: my cell signal was fluctuating. I normally get a strong five-bar signal in my office but sometimes it would slowly creep down to just one, and then back up again; other times I’d pick it up and there’d be no problem. Meanwhile, my iPhone 3GS showed a full signal.

The iPhone’s stainless-steel frame isn’t just there for style and structure; it’s also the phone’s antenna assembly. The black seams between its steel sections represent gaps between the phone’s Bluetooth/WiFi/GPS antenna and the larger one that’s responsible for the connection to the cell network.

If I bridge the gap between the two antennas at the bottom-left corner of the iPhone, it somehow interferes with the performance of the cell antenna. Press it into my palm, and the signal drops. Remove it, and the signal comes back.

It was my first exposure to a problem I’d see described all over message boards over the coming days. Same symptoms, same problem.

Apple’s formal statement regarding this problem is:

“Gripping any mobile phone will result in some attenuation of its antenna performance, with certain places being worse than others depending on the placement of the antennas. This is a fact of life for every wireless phone.”

Which, frankly, is an odd response. Apple has a point regarding “cold spots” on most mobile phones. But I have three other phones here in the office and no matter how I hold them, I can’t reproduce the same sort of dramatic impact as I can create by simply bridging the gap at the base of the iPhone with the heel of my left hand.

Furthermore, the problem simply doesn’t happen when the iPhone is wearing a case ... even Apple’s bumper case. So it’s definitely a physical “bridging” problem, not a “blocking” problem. It’s pretty clear that this is a problem unique to a phone that wears its antennas on the outside.

Naturally, this problem has received a lot of play online. That’s a shame, because it only tells a fraction of the whole story. It’s not necessary to hold the iPhone 4 in a specific way to avoid the problem. Quite the opposite; in my experiments, I found that there was just one position in which the signal degrades ...and it’s not even how I normally hold a phone.

Bottom line on this bit: be aware of the problem ... but overall, don’t worry about it.

A Golden Age Of iPhone Wireless

It’s an unfair issue to dwell on because the iPhone 4’s wireless abilities represent some of the true superstar features of the device.

Even on AT&T’s 3G network, this phone is an utter scorcher compared to the iPhone 3GS.

After running the SpeedTest app on both an iPhone 4 and a 3GS eight times in the same location ten minutes apart and throwing out the highest and lowest test results, I discovered that the iPhone 4’s average download speed was 15 percent faster than the 3GS.

Nice. But that’s not the big news:

The iPhone 4 is 4.4 times faster than its predecessor when uploading. That’s a high enough increase that I insisted that the iPhone 4 submit to an immediate drug test.

It’s due to the iPhone 4’s improved implementation of HSDPA (which arrived with last year’s iPhone 3GS) and its brand-new support for HSUPA. Yes, take a guess at what the “D” (download speed) and the “U” (upload speed) stand for in those respective acronyms. The upshot: the iPhone 4 can make better use of all of the improvements that AT&T has been making to its network, and it shows immediately.

Raw speed aside, the iPhone 4 is noticeably better at acquiring and maintaining a cell signal than its predecessor. I carried both my 3GS and the iPhone 4 around every day. Every time I noticed fewer than the full five bars of reception on the 3GS, I checked the iPhone 4 ... and it always showed a stronger signal. I made a side-trip to a location known for its spotty AT&T coverage and my experience there also pointed to some serious improvements to the iPhone’s signal reception.

And the hits keep coming. Thanks to an upgraded GPS chip, the iPhone 4 locks onto a GPS signal much more quickly than the 3GS. I also noticed greater accuracy. My location has a far lesser tendency to “drift” than it does on the 3GS, too. Which is a bit of a letdown because I was sort of enjoying looking down at my phone during my morning constitutional and seeing that a sudden leap 70 yards to the right and then back again within one second had increased my average walking speed to about 90 miles per hour.

You can also expect far greater WiFi speeds in certain locations. The iPhone 3GS and most other phones on the market today only support 802.11b and g. The iPhone 4 adds the much-faster 802.11n standard to its gunbelt.

And Now, Let’s Bring Out Your Headliner: Retina Display

The iPhone 4’s signature feature, the one that appears above the title on the movie poster, is the Retina Display.

It’s not enough to simply say that the iPhone 4’s new display offers “higher resolution” than the iPhone 3GS. It contains four times the number of pixels in the same screen size, so, yes ... quite right.

But that doesn’t quite cut it. The Droid X and the HTC Incredible and the Sprint HTC EVO are much higher resolution than the 3GS. You look at any of these three phones you think “Wow! That’s a super-high-resolution display!”

Sometimes when you look at the iPhone 4’s screen, you don’t know what you’re looking at. The dots aren’t “barely perceptible” ... they’re imperceptible.

That’s physics, son. You can argue with the man, but you can’t, I say, you can’t argue with the physics, courtesy of Discover Magazine, boy!

Well, at any rate, you’ll hurt your eyes trying to see individual pixels

And the intense dot pitch (326 dpi on a 960x640 3.5” display) is only half the story. The phenomenal impact of the display owes at least as much to its 800:1 contrast ratio as to its resolution. It can display an enormous range of light and color values.

In an optimal environment, looking at a photo — or even a paused frame from Pixar’s “Up” — is eerily like looking like a large film transparency on a light table ... an illusion that’s enhanced by the fact that the surface of the screen is laminated directly to the underside of the iPhone’s front glass. There’s hardly any gap between the pixels and the surface. I keep looking for faults and weaknesses in the image. I can only find them when I go into full-on Nitpick mode.

As a comparison test, I displayed an image of Holstein cows on the iPhone 4 and the Droid X. The Droid has an excellent screen (854x480 at 4.3”), but the superiority of the iPhone’s display was clear. There’s a point at which the Droid screen gives up and says “Okay. Let’s just say that the rest of this dark blotch on this cow’s hide is solid black, all the way down.”

The iPhone begs to differ: it wants to show you the texture of coarse, black hair on the side of the cow all the way through the shadow.

What’s the real impact of this superior display? Does it truly enhance your day-to-day use of the phone?

It depends on the kind of user you are. During the simple, dull process of tapping your way through application buttons and drilling down through hierarchical menus ... no, you won’t really appreciate the difference.

But when you’re browsing the Web, you’ll do a lot less zooming in to read pages. When you read an ebook, the higher resolution and the higher contrast between the “print” and the “page” makes for a more comfortable reading experience.

Obviously, watching movies and viewing pictures on the iPhone 4 is up on a whole separate level. In fact, during my camera tests of the iPhone 4 versus three other phones and a camera, I initially scored the Droid X and the other phones a little worse than they deserved. Only when I got home and dumped my pictures to my desktop display did I realize that the other phones’ cameras were significantly better than I’d thought ... particularly that of the Droid X. On the train ride home, I’d previewed my shots right on their devices. The Droid X’s screen wasn’t presenting its own photos with nearly the kind of care and fidelity that the iPhone’s was.

Obviously, many games will get a profound upgraded experience thanks to this display. But even a simple app like aSmart HUD, my favorite dashboard-mount speedometer app for my iPhone, is reinvented on an iPhone. On the 3GS, the speed and compass and other onscreen indicators look like a computer-generated display. On the iPhone 4, they look like human-generated artwork. Once again, you get the “medium-format color slide” effect.

All existing iPhone apps get higher definition text and standard UI elements “for free”; the iPhone’s OS automatically renders those things at 4x resolution. Only bitmapped artwork needs to be re-rendered by the developers to take advantage of the 326-dpi screen resolution.

I Take That Back: The Camera Is The True Headliner

The upgraded display is one of the features that redefines the iPhone for me. The camera is the other.

This will read as a backhanded compliment, but I’ll hold my nose and forge ahead anyway: the iPhone 4 is the first cameraphone that earns the honor of being thought of as “a real camera, with some limitations” as opposed to “a great cameraphone.”

My mental attitude is different when I shoot with the iPhone 4 cam. I’m not thinking “Gee, I wish I’d brought my real camera ... but I guess this cameraphone is better than nothing.”

When I’m shooting with the iPhone 4, my goal is to make real photos. And it’s an eminently attainable one.

Apple made a very smart decision: they upgraded the iPhone 4’s camera to just 5 megapixels instead of 8, which is what you’ll get with all of the “hot” Android phones that are arriving in 2010. Those cameras are slapping down more pixels but are they creating better photos?

Not according to my tests. I walked around with the iPhone 4, an iPhone 3GS, the Google Nexus One, and the Verizon Droid X, plus my Nikon P6000 point-and-shoot as a control. In nearly every shot, the iPhone 4 was the champ among the cameraphones.

The iPhone 4 camera has a wide dynamic range and it performs superbly in low-light situations thanks to its backside illumination image sensor (it scatters less light than the frontside illumination sensors; waste not, want not). The iPhone is perfectly happy to shoot in available light in most situations. Even in daylight, you see the benefits of the larger sensor pixels and the backside illumination. On the 8-megapixel Droid X, a clump of trees in the background is a spray of green static. On the iPhone 4, they have detail and vibrance.

It also has a new (for the iPhone) LED illuminator, serving as a primary light source or a bit of fill light to nearby subjects.

I love the iPhone 4’s camera. That said, it has two consistent and sometimes annoying foibles. First, when you give it a challenging scene in which the camera needs to either underexpose slightly and lose some shadow detail or overexpose and blow out a highlight, it’ll blow out a highlight nearly every time. But you can easily work around this problem, thanks to the iPhone’s simple “tap an area to set the exposure and focus zone” feature. If this were a real photo and not a “see how well the camera handles this” test, I’d just recompose the photo, and tap the area that was being overexposed. The Camera app would base its exposure settings on that hightlight.

The bigger problem is the iPhone 4’s easily-bamboozled automatic white balance system.

The camera appears to have great difficulty dealing with two competing light sources when they’re of different colors. It’s nothing that can’t be fixed with one mouse click in any desktop photo editor, but it’s still annoying ... particularly when it even messed up the white balance on a photo whose main illumination was the iPhone’s own flash. The Android-based phones tended to excel here, thanks in part to their manual override settings.

But I’ll defend the iPhone’s camera from two directions. First, I noticed a curious phenomenon: when the iPhone 4 “screwed up” a shot, the Nikon P6000 (the “real” camera) tended to make the same mistake with a blown highlight or a bad color setting. So the iPhone is in good company.

And secondly: the iPhone’s camera software is about a thousand miles ahead of either the camera app you get with the Droid X or the stock app that’s built into Android 2.2. The Android camera apps were a colossal pain in the butt to use. Non-responsive buttons, key features buried inside submenus, huge shutter lag ... on the whole, they aren’t apps that encourage you to take pictures for pleasure.

The iPhone’s Camera app is lightning-fast: I could take a sequence of rapid-fire shots just by twitching the button. It launches quickly, you can switch in and out of the app efficiently, it’s streamlined and elegant. Bottom line: it helps you to take pictures. It wants you to succeed.

Another keen feature of the iPhone 4: its new front-facing camera makes self-portraiture (and self-portraits-with-friends) a breeze. It’s just VGA resolution, but when you absolutely, positively, must get a picture of yourself with a friend, it’ll do.

The iPhone 4 camera, although a huge leap forward, won’t take the place of your pocket point-and-shoot. The real win is that for the first time, the camera that you happen to have with you wherever you go is now a very credible, “real” camera capable of taking printable, enlargeable, and frameable photos.

In fact, every photo of the iPhone that you see in this article was, in fact, shot with a second iPhone 4. I could have walked into the other room and grabbed one of my "real" cameras, but I had the other phone right here next to me and I knew it'd do a spiffy enough job.

Video, Video

The iPhone 4’s rear-facing camera also shoots 720P HD video at a full 30 frames per second. This feature isn’t quite the same sort of breakthrough as the phone’s still camera. It shoots terrific video, but you still need to append the suffix “... considering that it’s a cameraphone.”

It has the problems you may have come to expect from phone video. You can blame the software, blame the hardware, or blame your shaky grip ... whatever the reason, iPhone 4 video tends to be very jittery unless you take pains to keep the camera steady while you shoot and you try very hard not to move around. Some digital video stabilization would have come in handy here.

You’ll also experience the famous CMOS-censor “rubber shutter” effect as you pan across a scene. And don’t expect miracles from the audio, either. It can handle a nearby, centered subject very well, but any background room noise will quickly collapse into an annoying waterfall of vuvuzuela-like buzzing in the recording.

The iPhone’s new HD video feature certainly doesn’t signal a death knell for conventional video cameras ... not even for the popular Flip cameras. In side-by-side tests, the Flip Utra HD consistently produced steadier and more attractive video, with much better sound. That said, the video camera can shoot some astonishingly clear and sharp images, with punchy colors. See the photo gallery for a couple of still frames I grabbed from iPhone HD video.

And when the camera app is in video mode, it lets you use some of the still camera’s most useful features. The LED illuminator works in video mode (you can even turn it on and off in mid-recording), as does tap-to-focus. That means you can start a shot on your family in the foreground, and then tap on the Statue of Liberty to shift focus to the background. That’s a pretty cool trick for a cameraphone.

As with the still camera, you can tap a button and shoot video from the iPhone’s front-facing camera ... again, limited to VGA resololution. Hey, how’s anyone going to believe that you actually met the guy who played the dad on “My Two Dads” (no, the other one) unless you get some video of the two of you together?

iMovie for iPhone

Apple released an iPhone edition of their iMovie video editor. It’s a $4.99 download from the App Store and well worth the price of a “People” magazine.

iMovie allows you to assemble a fairly sophisticated video from all of the clips you’ve shot with the iPhone. Transitions, inserting photos from your camera roll, themes, titles, and background music are all supported. It isn’t the full edition of the desktop iMovie, but bloody hell! It’s a remarkable thing to be cutting a video together on a smartphone.

In fact, it might even be a more useful editor than the desktop edition. I often shoot video when I travel, but I almost never get around to editing it together. Producing a video always seems like such ... a production. But on the iPhone 4, it’s almost like playing a game on your handset. Editing video is exceptionally-well suited to a multitouch OS; it’s a snap to just drag in clips from your video library and push and pull them together like lumps of clay. The iPhone’s processor can keep up for you, move for move. It’s made me very, very keen to see a version of this app on the iPad.

The results can be uploaded directly to YouTube or MobileMe, or saved as an HD movie back into your video library. You can then email it to friends or copy it onto your desktop.

FaceTime

A forward-facing camera isn’t a new thing ... nor is the ability to video chat via a phone. But with the iPhone’s FaceTime feature, mobile video chat isn’t a stunt feature that you’ll play with once or twice and then completely ignore. And for a simple reason: unlike the rest of the video chat systems out there, it isn’t more trouble than it’s worth. If the desire strikes you, you can dial a number and be video chatting with someone seconds later.

Video chatting via FaceTime is almost anticlimactic. You place a phone call to another iPhone, or any device that supports FaceTime (more on this later). You have a phone conversation. At any point, you can press the onscreen FaceTime button. A second or three later, you’re seeing and hearing the person you were just talking to.

You don’t need to hang up and call a new number, you don’t need to set up an account on an intermediary service, and you certainly don’t need to have a long and detailed conversation ahead of time with this person to explain how to get everything set up properly.

All you need is a WiFi connection (FaceTime doesn’t work on the 3G network yet). The phone invisibly moves the call from the cell network to the WiFi network, negotiates with the other device, and starts everything spinning. Use of the WiFi doesn’t eat into any of your voice or data minutes.

Video is smooth and fluid; audio is crisp and clear. You can use the front-facing camera or shoot with the back cam, operating it like a camcorder.

It just plain works ... so long as your friends and relatives have iPhone 4’s, that is. But soon, thousands of non-Apple devices might be compatible with FaceTime: Apple is promoting it as an open standard.

(You are about to witness one of the greatest similes that will be published in any medium in 2010. Call in the kids and read this next bit aloud to them. It’ll be a cherished family memory for decades to come.)

It turns out that FaceTime is like an Egg McMuffin and not like Coca-Cola. Coke is a combination of many readily-available ingredients plus the mysterious, top-secret, and proprietary Merchandise “X” that turns a Cola into a Coke. When Apple created the FaceTime standard, they combined existing, open, off-the-shelf standards for network communication, handshaking, and media streaming into a new recipe, creating a technique that practically anybody can replicate.

So it’s certainly possible that by this time next year, FaceTime will be available on multiple handsets from multiple carriers, running on multiple operating systems ... possibly even including desktops. For now, it’s an iPhone 4-only club.

I’ll believe it when I see it. Apple has a couple of things going for it, though: they’ve had success promoting open standards that fit in with its business strategy in the past. And which when you think of it, FaceTime represents the strongest of all possible strong-arm tactics in family marketing.

“Well, sure, Dad ... I suppose you could buy an Android-based phone, if that’s what you really want,” a seven-months-pregnant daughter will say via email. “I guess I assumed you’d be buying an iPhone 4, like the one I have. Because, you know, I thought you might be interested in seeing your new grandson’s first steps and his first word and all of those other little milestones. Oh, well, no worries ... his other grandpa is buying an iPhone. I suppose little Tralfaz will just form an unseverable lifelong bond with him instead…”

iPhone 4 Potpourri

Let’s go around the horn and pick up a few bits and pieces that didn’t merit the full operatic presentation:

The iPhone 4’s battery life is just fine. The insides of a disassembled iPhone 4 appear to be at least 50 percent battery. The iPhone’s definitely up to the challenge of powering that power-hungry screen. Precise measurements of battery life are fairly meaningless but in the past five days of testing, the battery proved to be easily capable of powering the iPhone 4 through a day of conventional, intermittent use, or four hours of heavy use (walking around the city taking lots of photos).

It’s still a good idea to pay close attention to battery charge status. Many of the iPhone 4’s operations, such as recording HD video, are highly processor-intensive. It might take you a few days to figure out how many miles you can go on a single tank of gas.

Audio quality. The new iPhone adds a noise-canceling mic that has a definite positive impact on sound quality. Alas, it doesn’t kick in when recording video ... and there’s been no upgrade to the iPhone’s built-in speakers. But it seems to be a help when issuing voice commands in a car.

Volume and clarity are Adequate when using the iPhone’s speakerphone, but it’s still about one click or two too soft.

And Now There’s A Gyroscope. An internal digital gyroscope allows apps to sense the minutest changes in the iPhone’s pitch, roll, and yaw. A game like Ngmoco’s “Eliminate: Gun Range” shows off the level of precision possible with the new hardware. When you swing the sight of your gun through Eliminate’s gun range, it feels more like you’re operating the iPhone’s video camera; the slightest movement of the phone translates to an instantaneous and precise shift in your point of view. In accelerometer-based gaming, it’s more like twitching a joystick and indicating a vague direction.

There are obvious uses for this precision in augmented reality apps. But clearly, the primary beneficiary of this new gyroscope will be the iPhone’s game library.

iOS 4 and the Coming of the iPad Nano

I said at the top of this review that the iPhone 4 felt like a “new” iPhone as opposed to an “improved” one.

Clearly that’s because of the new display, which truly dazzles. And the still camera. If you’re more of a “snapshot” photographer, it won’t make much of an impression on you but anybody who values the ability to capture a great image at any moment will be pretty thrilled with the iPhone 4’s camera capabilities.

But the new iPhone 4 hardware coupled with the new features of iOS 4 elevate the iPhone’s game considerably. It shares so much DNA with the iPad — including its actual CPU, Apple’s own A4 — that at times, it feels like a mini-iPad.

At times, you can even use it like a mini-iPad. Many of the iPad’s most convenient and powerful features, like the mechanism for moving your documents into and off of the device via iTunes or the cloud, are part of iOS 4. I actually wrote last week’s print edition of this review (a merciful 600 words) on the iPhone 4, using a Bluetooth keyboard. Writing and editing operations were responsive and zippy, a notable improvement over the 3GS.

Yeah, yeah ... big deal. “That kind of thing has been possible on Nokia and other kinds of phones for years.” If you’ll scroll back, you’ll see that I went ahead and made that very point right at the top.

Much of the strength of a piece of technology comes not via the features that it presents, but by the perceptions and expectations it inspires. Is this thing in my shirt pocket a phone? Is it a content-consumption device? Is it a palmtop computer?

On that basis, what happens when my ebook reader has a rudimentary web browser?

Should I be disappointed that it does such a poor job of reformatting every page? Or should I be delighted that it even has that feature to begin with?

It’s overreaching to say that the iPhone 4 defines a whole new class of phone ... much less a whole new class of computing. No. It’s just superb next iteration of a phone that was pretty fab to begin with. It doesn’t even complicate consumers’ buying decision. Out with the old models, in with the new ones: the 16 gig model is $199; double the amount of storage for another $100. But it sharpens the distinction between the iPhone and 2010’s impressive graduating class of Android devices. A month ago, I think you could have said that the differences between an iPhone 3GS running iPhone OS 3 and those of a Nexus One running the new edition of the Android OS were largely philosophical and political. Today, iPhone and Android are once again two very different beasts. Declaring one to be the winner over the other is like betting on a fight between a hippo and a giant octopus. Each will have its fans and its supporters, but these are clearly two beasts with two very different ideas about how to stay on Darwin’s good side.

The iPhone 4 isn’t a revolution. But damn, it’s interesting. It’s that first little turn of the focusing knob that makes the line between “phone” and “computer” a little tougher to make out. It seems to beg for high expectations.