Yesterday I went to the Apple store in Santa Rosa and had a look at the iPhone. A short while into my stay there, I asked one of the employees to show me what it does. This turned out to be a very good thing as he knew much more about how to get around on the thing than I did. Having a live/personal demonstration by an Apple rep on the iPhone I highly recommend for anybody curious about what it can do. Though I didn't buy one (yet!), I left the store very impressed with the iPhone. It is an amazing tool - the hype is not exaggerated.
See a tour here:
http://www.apple.com/iphone/usingiphone/guidedtour_medium.html