Hi, is there any iphone that comes unlocked with a contract from a carrier ? I live in the US but I'm overseas about 9 months out of the year for work. Could I get a phone here with 2 year contract and change to a cheaper plan for when I'm overseas? Is it possible to change the monthly plan to something that would allow me to pay less because I'm overseas ? While I'm overseas, I plan to get another sim card anyway..