Buying a US Iphone for UK - Sim swap enough

Hi,

Had my eye on an Iphone since the release and wanting one badly.

Does anyone know if I can import a US version and put a UK sim inside? I see they are already being sold in £. I just don't want to buy one and realize its locked to AT&T making it a useless but pretty coffee mat.

well hopefully some one can come up with the unlock solution...