I have a 3G iPhone on a US AT&T contract. I may be moving to Malaysia (Kuala Lumpur) this year and I am wondering about just bring my iPhone with me and getting it to work there. When I visited last month, it worked fine. I am presuming I would ditch my AT&T-supplied SIM card and replace it with a Malaysian-bought card. Will this work or is this where a "locked" iPhone comes into play?