This weekend, Apple released its third generation iPhone, the iPhone 3G S, an incremental update to the previous version, the iPhone 3G. From a form factor perspective, the 3G S is identical to its predecessor. But under the covers, things have changed quite a bit. Some of these changes will result in better performance immediately, while others are a bit further looking and will require upcoming wireless carrier updates.

Apple says the S in iPhone 3G S is for "Speed" and claims it is "up to two times faster" than the iPhone 3G. As always, Apple's claims should be taken with a grain of salt. In use, applications launch faster on the 3G S, but run at the same speed as they do on the original iPhone 3G. Typing is snappier, with letters popping up onscreen immediately, instead of having a short delay as before.

Some upgrades will result in improvements further down the road. The iPhone 3G S sports an improved graphics processor that could be taken advantage of by upcoming games and other titles. And while the iPhone 3G S supports next-generation HSDPA wireless technology that hasn't been deployed yet. When it is, those in covered regions should experience a dramatic performance improvements.

Apple iPhone 3G S
It may look the same as its predecessor--exactly the same--but the iPhone 3G S packs some new features under the suddenly staid looking exterior.

New hardware

The iPhone 3G S also includes a dramatically improved camera, answering one of my key complaints about the previous models. The improvements come via both hardware and software. From a hardware perspective, the camera now sports 3 megapixels of resolution (vs. 2 for the previous two iPhones) and includes built-in auto-focus as well as a cool tap-to-focus feature, where you tap an area of the live preview screen to manually set the focus. The camera can also shoot VGA video, and you can edit the video right on the phone and upload to YouTube and MobileMe.

Apple iPhone 3G S
Not only can the iPhone 3G S shoot video--finally--but it actually provides on-device video editing as well.

Software

On the software end, the iPhone 3G S comes with numerous improvements, though most of them--like cut and paste, better support for the landscape keyboard, and true MMS, come via the iPhone 3.0 Software Update, which is available free to all iPhone customers. Those software features that are unique to the iPhone 3G S are mostly underwhelming. They include Voice Control and Compass.

Apple iPhone 3G S
Two new software applications are unique to the iPhone 3G S: Voice Control and Compass. Neither are hugely desirable.

Voice Control is sort of an odd retro feature that lets you control certain iPhone functions with--get this--your voice. You can say contact name or number to dial the phone, for example. And it works with the iPod software, so you can say the name of an artist or album to play music, and ask it what song is currently playing. It works with numerous languages, which is excellent, but it requires you to physically press and hold the device's Home button to activate, making it less than viable for the automobile, which is potentially its most compelling use.

The Compass application is laughably silly, but the underlying directional functionality also works in Google Maps, where it is decidedly more useful. With an iPhone 3G S, Google Maps rotates the map to match the direction you're facing, a subtle but useful upgrade.

[ To learn more about the new iPhone software, check out Quick Take: iPhone OS 3.0 Software Update. ]

Final thoughts

While the original iPhone 3G was a major update over its predecessor, the iPhone 3G S offers a subtler, less revolutionary update, and one that isn't a no-brainer for existing iPhone 3G customers. This is especially true for those that don't qualify for upgrade pricing under AT&T mysterious and Byzantine pricing scheme: If you can get the iPhone 3G S for $199, it's a tough call. But if you have to pay more than that, I don't feel it's worth the upgrade at all. (As a result, I won't be getting one of these devices until early next year.) Obviously, few Apple users take such a logical stand when it comes to buying the latest and greatest, and one might expect many, many iPhone users to upgrade regardless of cost. They'll be rewarded with what is clearly the best smart phone currently on the market.