Worldwide Distribution of Unlocked iPhones

Apple has an agreement with AT&T to sell iPhones enabled with only the latter’s network. However unlocking the iPhone is not that uncommon, if not easy.

Number of iPhones sold till date : 3.75 million
iPhones believed to be unlocked : 1 million

Number of iPhones expected to be sold by end of 2008 : 10 million
iPhones expected to be unlocked : 2.5 million