i can get 2 days out of mine pretty easy. and i usually play music or pandora in my car with it for 30 mins to 1 hour a day. maybe another hour a day between internet and other stuff, then all my calls and text.
i can pretty much do whatever the hell i want with it and get a whole day, many hours of playing music, games and internet and still have over 15% at the end of the day.
the power moniter thing really helps, under android widgets, you can turn off gps, and other stuff when your not using it so it doesnt eat up your battery, and mess with screen brightness.