Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Not sure how to post a screenshot from my phone, but initially I was keeping track of the battery life.

Three random instances where I kept track:

34 hrs of standby + 5 hours of usage with 30% battery left
20 hrs of standby + 5.5 hrs of usage with 24% battery left
23 hrs of standby + 6 hours of usage with 17% battery left

I could probably squeeze out 7 hours of usage from a full charge if I let it go all the way. My usage is a mostly heavy 3G web browsing with safari (i never use wifi) and occasionally some gaming, texting, and calls.

And with standby time alone, I lose 3% battery life every 10 hours, which IMO is very good
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.