ok i what the iphone 3gs but have t-mobile. my plan was to go to apple and get it there, but i guess you have to already be on AT&T. I know one way to get it is sign up with AT&T and then cancel etc.. but i don't want to go though the long and $ process. So i was thinking of just getting one off ebay or craigslist( good idea or no??) if i end up doing that.. Whats Next to get it to work right?... HELP!!