garym114 wrote:
For AT&T the data plan for tethered phones is Data Connect. The $60 plan is 5GB. The feature can be turned off and on but I don't know about prorating. You don't need their software. Just create a dial up connection to the phone via bluetooth or USB cable.
AT&T data plans for plane phones. Not for PDAs or smartphones. The have another for them.
Wikibooks - AT&T Mobility FAQ/MEdia Net Configuration - how to
AT&T appears to tolerate, or at least not to monitor actively, tethering of phones that have the Web access feature installed. The feature was called MEdia Net, and is now called just Data Plan. It costs $15. per month, or when combined with 200 text messages per month, $20. per month. As noted, you use it by creating a dial-up connection. I have two phones with this capability, one of which used it almost daily for several months with no problem. AT&T's 3G service is pretty limited, but where it is available, the tethered connection operates at 3G speed.