Have you notice the difference in iPhone 4 battery life between setting up iPhone 4 as a NEW set up vs RESTORE from backup? I had my iPhone 4 restored from backup image initially. Battery life was dismal. I can see the battery % dropping every few mins while idle. I have done complete device restore (still using backed up image from iPhone 3G) and network reset without any improvement. Searching through Apple KB, Apple recommended updating iPhone 3G/3GS to iOS4 then backing up prior to upgrading to iPhone 4. I didn't want to upgrade my old iPhone 3G to iOS4 as I wanted to sell it with 3.13 firmware instead of iOS4. Maybe that may have been the cause of my battery problem. So I did factory restore my iPhone 4. This time, I didn't restore from prior backup. I set it up as a NEW iPhone 4. Reinstalled everything manually. Result? Amazing battery life other people are reporting. I am not sure because my restore image was from 3.13 firmware or not. Someone can chime in with their experience on 1) restore from 3.13 firmware vs new set up, 2)restore from 3.13 firmware backup vs restore from 4 firmware backup, or 3) restore from iOS4 vs new set up.