im pretty sure they all work on at&t. if it doesnt already have the APN detected and working, you can always enter it yourself. try arhd. cant go wrong
In case u didn't see it already, be aware the tmo-us sensation can't use ATT's 3/4G (3.5G?) network. I experimented with a buddy's att sim card and only got EDGE where his inspire got full bars of H+. I hear the Canadian sensation works great with att
well if your using a tmo sensation, then you cant get 3g/4g speeds due to the phone/network different radio bands. to get 3g/4g on att you need a bell, telus, or telstra sensation i think