I have been using a iPhone 3G for a couple days, about the same as I use my Curve, and the battery life SUCKS. Even with 3G off, WiFi off, etc it's still not good. Turning off Push is not an option.

Also, as NJ said, none of my old iPod devices will charge it. Not an iHome, not a car charger, not even a wall charger. I gotta say, other than the internet aspect of this, I prefer my blackberry.