Well, this is weird. (Or maybe I'm missing something?) To be able to tether in iOS 4 with AT&T, you must first call them. However, it appears as if I do not have to do so with mine? Please Register or Log in to view images I tried enabling it with someone else's iPhone 3GS (iOS 4), but they must first call AT&T to activate it. I noticed that before they could do anything with tethering, the phone first connected to the internet / AT&T (the spinning black circle on the tethering tab) and then displayed the message of contacting them. I DID restore from a backup that had tethering enabled on 3.1.3, though. Maybe that had something to do with it? Could this possibly mean that restoring from a jailbroken backup allows you to bypass AT&T's activation and tether without them knowing? There's no way I'm paying $20 more to use the data I'm already paying for. Share your thoughts and tell us if the same happened to you.