When I read your post I thought you were playing repeat from Super Troopers.....
Anyways,
I used to work for Cingular (back before and immediately after they purchased ATT Wireless), and although it would probably work, it is kind of a jacked up way to do things. I would say you are better off jumping on ebay and buying a "jailbroken" ( terms from apple homos) phone. Then of course, while I'm making suggestions, I would suggest not even buying an iphone anyway (just personal opinion, I think they are gay).
Edited for too many rainbows, made my post look bad.