I know that this article is a bit off-topic for my blog but so many of my friends have been complaining about the battery life on their iphone since they upgraded to IOS5 that I felt it was worth sharing this trick. There appears to be a bug in IOS 5 which makes the phone constantly check the time zone in the background. As a result your battery rapidly looses charge when you are not using the phone. Here is the trick to turn that off until a fix comes from apple.
Go to settings->location services-> scroll all the way to the bottom to system services->turn off setting time zone. That is it.
I have noticed a substantial increase in my standby time. Hope it does the same for you.