So the iPhone 4 is rated at 300 hours. I am assuming this might be with 3G off, WiFi off, Push off, GPS off, no push mail, Bluetooth off. 300 hours = 18000 minutes or 3 hours/180 minutes per 1% of charge. Today my iPhone 4 dropped from 100% to 88% in 4 hours. No calls, no video, no gaming. Sent 1 email. WiFi on, 3G on, GPS on, BT off, Push email on. Screen black and locked most of that time. I'm guessing either: 1. I have a lame battery. 2. The mail app somehow is killing battery life? 3. Multitasking still uses too much battery in the frozen background state, though in my case I don't have hardly any apps in my multislider. Oddly enough it was 100 when I went to bed last night at 1:00 and was still 100% or 99% when I woke up at 6:30. But I have noticed that my battery isn't going as far as I thought it would compared to my 2 year old 3G. And I'm using my 3G now Touch for a dedicated music player. But nowhere near no 3 hours per 1% drop.