iPhone4 Battery Issue / Solution

After a hectic pre-ordering process due to AT&T's bogged down servers, I received my new iPhone 4 via Fedex a day before it actually went on sale in stores!  To my delight, after a few days of use, the new device was as wonderful as Apple had promised:  The screen is amazing, the new A4 chip performs great and I seem to be unaffected by the reception issue of AT&T.  That said, I was definitely noticing that my battery was really draining quickly, even though my use of the phone was rather limited.  Apple had touted that the battery was supposed to last 300 hours on Standby mode, but my battery was barely lasting through my day (6:30am - 1am) while mostly on Standby.

What changed?  My old iPhone (1st gen - 3 years old) had no battery issue at all!   So after some deductive reasoning, I figured out that it had to do with the new multi-tasking functionality.  Specifically, the Google Maps app.  Apparently, if Google Maps is left running (i.e. left open in your Multi-Tasking bar) then the GPS functionality continues to track your every move, which is a huge drain on the battery!  Thus, I opened up the multi-tasking bar (double click the "Home" button) held my finder on the Google Maps icon, until all the icons began to wiggle, and then tapped the red minus (-) sign on the top left corner of the icon to fully shut down the application.  Voila!  The GPS tracking was turned off and my battery life was restored!!  I assume other apps could have this same effect, not mail / internet / etc, but other GPS apps that are actively communicating with a server, but I didn't have any of these installed.

Hope this helps!