My battery life is perfect until I start using the screen and do some 3G browsing. Then it drops at a rate of about 1% every 4 minutes or so.
this is the way mine behaves, too. when it's idle, battery is great. as soon as i start to use it, it starts to drop rapidly. lock it and it stays good. all i usually do is text, check work emails, etc. but it seems just having the screen on is a major problem. i've also noticed that if i have wifi enabled but there isn't a network to connect to, it drains the battery much faster.
att 4s