US users -- has anyone tried to buy an official unlocked iphone either from another country (Canada, UK, etc.) or from an online site? Is there any reputable seller in Canada that will sell/ship an unlocked iphone to the US? Otherwise, I was thinking of making a trip across the border to get one. It doesn't seem to make sense buying it from any other country (even thought it might be convenient because of existing travel plans) where the power plugs are different. I figure the freedom of changing carriers and the ability to simply not have a data plan would make it well worth it.