I've got the iPhone. And I've got an unlimited full rate data with it. Ok, the network only supports 3.6 Mbps currently but still. And yeah, denying users the use of tethering is not even an option. It's been a standard feature in phones for years

. It's not a favor from the carrier to "allow you to use it". Just like denying the users the use of VoIP is not quite an option.. internet use is internet use. There's a fair use clause but I've never heard anyone get the bad end of that... Although AT&T seems to be killing the apps for the rest of the world too.. go figure.