The focus interface, the extremely cool part, is done through software. Apart from being able to simply focus on things that are relatively close to you (as opposed to a permanent setting of infinity on a small lens), it's the way the focusing works from a UI standpoint that's so cool.

Not only because of focusing, but also metering, which makes it possible to capture photos with the 3Gs that were previously impossible with the older sets.

BTW, the people that I was referring to were certainly not talking about the 3Gs' ability to simply capture moments. They were genuinely impressed with the quality of the photos. I suppose if taken in the context of other camera phones they may be great, but they're not P&S level. Not even at the level of a sub-$200 P&S.

In terms of convenience, I agree, nice to have it around. But if you want/need better quality, even if only a little better, then you're carrying a camera as well and the one in the iPhone is largely duplicated and unused. It's going to be cool for live barcode scanning though.