what? you put it in a no contract iphone, when you open the iphone 3gs for the first time and try to turn it on, was it already activated? or did you have to plug in a sim card that was already on contract to activate the phone?
Its not pre-activated. Have to either sign up with AT&T via iTunes or put in a sim from another AT&T phone and then sync it with iTunes, which adds the data plan to that account.