Hello, Well with the christmas season upon us, I've got an iPhone 4 related question. I'm considering getting an iPhone 4, my mind is just about made up, except for one little question. If I buy it here in the UK, and then later his year when I return to the USA, will I be able to use it there too? I'm sure it may have to be unlocked, but can I obtain an AT&T sim chip for it? Because once I leave the UK, I may not be coming back for some time, and the roaming charges just wouldn't be worth it. All the best, Jacob.