There's a reason why Apple called this the iPhone 3GS for Speed and not the 3GC for "compass" or 3GV for "video recording." Speed is the central upgrade here, and probably is the single biggest reason you would upgrade to a 3GS from a 3G. And if you're coming in as a virgin iPhone user, there's definitely no question: The 3GS is worth an extra $100.

That declaration may be weird to most of us since we usually look for features, and not specs, when we're evaluating phones—and iPhone 3GS doesn't blow us out in the feature department. Instead, it's like getting a bigger TV or a faster car. Your old machine works just fine, but once you've tried the new one for a week, you'll never want to go back, even if it costs you a little extra.

Like we said, from the outside the 3GS is exactly the same as the 3G. It's slightly heavier and has glossy text on the back, but if Steve Jobs whipped one out in public before it was announced, you wouldn't have been able to tell the difference. By holding the 3GS next to the 3G, you'll notice that the screen is slightly more reflective because of the new fingerprint resistant oleophobic coating. It even has a little bit of a rainbow effect if you reflect a monitor with it. Surprisingly, the coating actually works in preventing a good deal of fingerprints and face grease, and it allows the phone to still be smooth and usable even if there are fingerprints on the surface.