After 2 iphone replacements for severe battery drain, updating to 5.0.1, and countless hours of trial and error... I have come to the conclusion that iMessage is the BIGGEST part of the battery drain. After testing this fix on my device I can report a MAJOR difference in battery drain. Please try and post your results here: * Restore iPhone as new (DO NOT use a back-up) * Immediately after restore, turn-off iMessage * Reset Network Settings TWICE. * Restart phone by holding power + Home button. * LEAVE iMessage OFF NOTE: You must follow these instructions. It seems that just turning off iMessage does not stop it from doing background operations/connections. Enjoy you new iPhone without the battery drain.