My iPhone 3GS has terrible battery life. I got it 5 days ago, and merely checking a couple of sports scores drops the battery down like 5%. I'm completely unjailbroken, and when I say "checking sports scores" I mean going to ESPN for 10 minutes after the phone had been fully charged. I have it hooked up to the computer now for the 3.1 update and I hope that helps some. Otherwise, the iPhone barely makes it through an entire day of work. Yes, I have 3G off. Yes, I have bluetooth off. No, I'm not playing games, music, or video It just sucks. I'll update this if the 3.1 update magically changes something.