Wow - I'm surprised by the need for the extended battery. I'm using the standard battery right now. Yesterday, I was on the phone for 1 1/2 hours, Slacker for another 2, about an hour on the internet, used the camera and gallery for 15 pictures, and checked email, FB, other social media periodically. After 15 hours of use, I plugged it in and went to sleep with 10% still left.
Now, my brightness is set at 5%, Gmail is pushed every 30 minutes, work email every 2 hours. I check FB and Twitter manually and I make sure to actually exit out of Opera browser. I used 3G exclusively (WiFi is only on when I know there's a wireless network).
The battery on this phone is much better than the one in the Razr (not the Maxx).