Looks like AT&T "detects" if you're attempting to use tether on the Nexus S. I got the phone and it works fine. LOVE the nearly one gig of space for apps versus 196 MB of the N1. But...with the inability to use tethering, it's going back. Not like I tether a lot, rarely actually, but I will not pay an additional $20 per month for something that's rarely used.