I already answered in another thread, but to put the information also here you can edit the powermanagment settings in /etc/pmconfig instead of running the commands on startup

I charge my phone at 21:00 each night or so, and 3G connection is continuously on.
During the day I work, so usage is very minimal.
It's to say that I am impressed that when I chatted for nearly 2 hours on it the battery finally gave up at around 18:15 giving me the "red" status.

My brightness is set to the near highest setting.
Not to mention that I have GPS positioning enabled as I go online.
I was also installing and testing different MSN plugins too and also switching between them during testing and thus logging on and off all the time during those two hours.
Meanwhile, Xchat (IRC) was running as well with about 7 channels open.

Now that I am writing this post, I notice that I keep losing track of perspective when it comes to battery life on devices like this.
I was disappointed at the time when the fun was over after "only" 2 hours of chatting.
And yet, if I would attempt the exact same scenario with my Nokia N95 (which has a smaller screen with less pixels, slower CPU etc. to boot) it would not even come close to all this performance on one single charge.