I think i messed up pretty bad. My 2g phone has been having issues with a very flakey lock button (gotten around through use of sbsettings and auto-lock). I just put the phone in dfu mode but pressing the "turn off" button in sbsettings and holding home in order to upgrade to 3.1 from 3.0. Now the phone is off, iTunes doesn't recognize it, and i cant turn it on. Disconnecting it and plugging it in doesnt turn it on in dfu mode (like it does in a normal off position). Help! i need ideas fast!

and the phone doesnt show up at all in itunes, not even an error to indicate it finds the phone

Are you using itunes 9.0?

It's always more helpful if you give people a little more history about your iphone; so they can better understand your problem.