Ok, well I've been getting around 6hr usage time and 10-12 standby normally on my battery with the iphone 4, not bad, but today I somehow got 9hrs usage and 14 hrs standy and I'm still at 19%! And I'm not sure why it jumped so much. There are only three things I noticed that I did differently today than normal. 1. I started using my iphone 4 full time, I have been using my iphone 3G as my ipod to save on battery use of the 4, but today I left my 3G at home so I used the 4. I don't see how using my phone more would cause this. 2. Today I haven't been closing my apps in the task manager. Usually I close every program in the task manager when I'm done using it to save memory and to conserve battery, but today I didn't do that but I'm not sure how that could make the battery last longer. 3. The a/c in my car was fixed yesterday. I do service calls for my job, so alot of the day is spent in my car driving from job to job. Since I got my iPhone, the a/c in the car has been broken, but it was fixed yesterday and today was the first full day I've had working a/c, could this possibly be the reason the reason the battery lasted longer? Would heat really have that much affect on the battery? I live in florida, so without the a/c it was probably around 90 degrees in the car even with the windows down and now with the a/c its a cool 75 degrees, but could that have that much affect on the battery life? Or was it one of the other things? Any other theories?