[cpjr]

True, you can attempt to add another type of "data" plan onto your account through AT&T, it may work for awhile....but they monitor that stuff pretty heavily. They will be able to see your using an Iphone (your phone serial# is transmitted, regardless of simcard) and if they catch it you'll get a mean letter stating that if you do not add the proper "Iphone Data Plan" to your account, then they will.