A: The extra $100 for theVoice control: This is a welcome and nifty feature that performs well. Not only can you make calls using only your voice, but also you can use the iPod player. It's particularly useful if you'll be using the iPhone while driving. Video recording: Another feature that was long overdue. The video quality is quite good and the editing tool is unique and very easy to use. Accessibility options: The 3GS is the first iPhone to offer a broad range of accessibility feature, like Voice Over, which will read a description of the onscreen controls. Other options will further assist visually impaired users. Compass: The compass and its integration with the Google Maps feature are neat, but I don't see myself using them that much, though you might feel differently. Better battery life: The iPhone 3GS promises double the battery life of the iPhone 3G. We're still testing our iPhone 3GS, but it did seem to last longer than its predecessor did during preliminary use. I'm hoping that it lives up to expectations, as short battery life is one of the drawbacks of both the original iPhone and the iPhone 3G. Faster performance: We have found the the 3GS is faster than the iPhone 3G. It opens applications more quickly and turns on in half the time. If price is your main issue, then I think you'll get a great iPhone experience with the $99 iPhone 3G. But, if money is third our fourth on your criteria list, I'd say that you'll enjoy the added features from the iPhone 3GS.