Apple Thoughts: How is Your iPhone Battery?

"Apple is investigating complaints about iPhone battery life on the new 3.1 OS. Some users point fingers at new behavior switching between 3G and EDGE modes."

Numerous reports about shortened battery life after upgrading to 3.1. Apple has even contacted some users and sent them an attachment that allows batter life logging, in hopes of narrowing down the problem. In one thread, several users report that just letting the battery run down to empty and recharging seemed to fix their problems. I haven't had any problems like this, have you?