due to an unfortunate time capsule corruption during a clean upgrade to lion a couple of weeks ago, i lost the "connection files" that iTunes kept in my home folder, so basically had to re-sync the phone to a new computer. something got off in the process. my weather and stock apps dropped their settings, and my battery life went down the tubes.
The phone would be completely dead by noon. and then again by 6 pm, and pretty low by late evening. i stopped all apps, killed all location services.
during this time (3-4 days) the phone completely ran out of battery about 5 or 6 times, probably only happened 3 or 4 times before that (original 4 on launch day)
the only thing that helped, was a clean install of 5.0.1. now it's back to it's normall battery life. (and i've also upgraded to 5.1 since)