Unfortunately, there's not much you can do with the G.P.S. According to Apple, the iPhone's G.P.S. antenna is much too small to emulate the turn-by-turn navigation of a G.P.S. unit for a vehicle, for example.
Instead, all it can do at this point is track your position as you drive along, representing you as a blue dot sliding along the roads of the map. Even then, the metal of a car or the buildings of Manhattan are often enough to block the iPhone's view of the sky, leaving it just as confused as you are.
There are lots of small software improvements. The four-function calculator now turns into a scientific calculator when you rotate the phone 90 degrees. There's an address book search box, parental controls and instant language switching. (That feature is made possible by the on-screen keyboard, with keys that change to reflect the language you've selected. "That's really hard to do on your BlackBerry," says an Apple rep.)
And speaking of the BlackBerry crowd: Apple also says that the iPhone works better with corporate systems, like Microsoft Exchange and ActiveSync.
Note, though, that these software tweaks aren't iPhone 3G features. They're part of the free software upgrade called iPhone 2.0, which will be available to the six million original iPhones, starting Friday. For $10, even iPod Touch owners can get this upgrade.
Unfortunately, most of the standard cellphone features that were missing from the first iPhone are still missing. There's still no voice dialing, video recording, copy-and-paste, memory-card slot, Bluetooth stereo audio or phone-to-phone photo sending (MMS). And when the battery needs replacement after a couple of years, you'll still have to pay Apple $86 for a replacement.
Plenty of Appleholics have expressed dismay at how little the handset has changed. They'd gotten their hopes up for the second-generation iPhone: video phone calls! iPhone Nano! 3G hovercraft!
But there is one towering tsunami of a feature that may well shut them up.
It's the iPhone App Store: a central, complete, drop-dead simple online catalog of new programs for the iPhone. Hundreds will be available when the store opens Friday, with thousands to follow. You browse, download and install new programs directly on the iPhone; they don't have to be transferred from a computer, and you don't have to hack the phone to use them. Most of the programs will be free or cheap.
Apple has demonstrated 16 of these programs, including an instant message program, an eBay auction tracker, medical references and a touch-sensitive musical keyboard; the best of them exploit the iPhone's orientation sensor, wireless technologies and other high-tech components.
One coming program, called iCall, will give you free phone calls when you're in a Wi-Fi hot spot. Another, called G-Park, exploits G.P.S. to help you find where you parked. Yet another, Urbanspoon, is "a cross between a magic eight ball and a slot machine:" you shake the phone, and it randomly displays the name of a good restaurant nearby, using the iPhone's G.P.S. and motion sensor.
You can also expect to see a time and expense tracker, home-automation remote control, voice recorder, Etch-a-Sketch, a recipe box, tip calculator, currency converter, e-book reader and so on.
Above all, the iPhone is about to become a dazzling hand-held game machine. The games revealed so far feature smooth 3-D graphics and tilt control; in one driving simulator, you turn the iPhone itself like a steering wheel, and your 3-D car on the screen banks accordingly. Other games exploit the multitouch screen, so you and a buddy can sit at opposite ends of the screen and fire at each other.
In short, the iPhone is about to become much more than a phone. And here's the best part: the App Store is also available to the original iPhones and the iPod Touch.
So the iPhone 3G is a nice upgrade. It more than keeps pace with advancing technology, and new buyers will generally be delighted.