I guess u already heard the news - some people counted the number of iPhones sold by Apple and the one registered to various official service providers. There seems to be a 1 million iPhones unaccountable, and the only explanation for it is that they were unlocked and being used in other networks.
Duh… even in Romania, where the iPhone is still to be launched there’s a thriving market for unlocked iPhones – I saw at least 5 people in the street using them.