Apple Now Selling Unlocked iPhone 4 in U.S.: As we had predicted, Apple has started selling unlocked (GSM) iPhone 4 devices in the U.S. early this morning.
If you don�t want a multiyear service contract or if you prefer to use a local carrier when traveling abroad, the unlocked iPhone 4 is the best choice. It arrives without a micro-SIM card, so you'll need an active micro-SIM card from any supported GSM carrier worldwide.
Pricing starts at $649 for a 16GB model and $749 for 32GB model. Both White and Black models are offered.
The main advantage of buying an unlocked iPhone is for international travel. The U.S. only has one network (AT&T) which fully supports all the features of an unlocked GSM iPhone. T-Mobile is compatible with voice calls, but the 3G network is not compatible. The higher price of the iPhones reflect no-contract pricing as well as the unlocked status of the device.