Ipod Touch Wont stop restarting! PLEASE HELP!

Hello,
My name is Larry and i bough my ipod touch 3rd generation about 3 months ago.
and i was talked into jailbreaking it about a month ago. all was fine up until a week ago when i tried to update the software to ios 4.1. my friend told me that i had to restore it from the jailbreak before updating so i reseted it in the settings option on the ipod (not through itunes)
now it wont turn on! it is stuck on the apple logo ang even after i let the battery die the problen persist i tried everthing hold home and sleep for ten secs and resetting it in itunes but itunes does not recognize my ipod PLEase help me?!