I'm interested in buying a couple of iPhones sometime this fall to rip my friends off when I go back home outside the US. There's an official premium for each model to get them as gifts (with no plan), but I've heard that it's actually cheaper to buy one with a plan then cancel the plan. Does anyone know if this is actually possible, and feasible for someone who already has an iPhone with an AT&T plan? I.e. do they only allow one customer to sign up for one plan at a time? Any advice would be appreciated.