The iPhone 3GS combines two sets of advances. The first group is available only to purchasers of the new hardware. The rest of the features are part of Apple’s iPhone 3.0 software upgrade, which is offered free to those with earlier iPhones. (iPod Touch users can get the new software for $10.)

I’ll talk about the hardware-based features first. As promised, Apple has indeed ramped up the speed with which the new phone performs tasks like launching apps, loading web pages, and displaying graphics. Apple claims speed boosts of up to two times of what the 3G delivers, and in some benchmarks cites even better performance. I haven’t done scientific measurements, but you don’t need a stopwatch to notice the new phone is zippier than its predecessor. I appreciated getting box scores faster and videos playing sooner in the MLB.com At Bat application, and it was clear that web pages loaded faster. In the case of a game like Tiger Woods Golf, the boost is significant enough to make me more likely to play when I don’t have much time.

Photos were a weak spot in previous iPhones — they weighed in at a measly 2 megapixels — but the iPhone 3GS…