My iPhone 3GS has been perfect since day 1. Tonight I had it all working fine, got it out of my coat pocket played a video I took, put it back in coat pocket. 10 mins later got it out to check email and nothing. I must mention that no-one banged into me or anything like that. It won't turn on or charge, is there a reset method or anything? Have plugged into my iMac but nothing. Please help!!!