What's Different About Apple's Newest iPhone

Apple is betting that enough consumers will think that the flexibility and freedom of its newest product -- an unlocked (and substantially more expensive) version of its best-selling phone -- is worth it and on Tuesday began selling it through the Apple store.

The units, which are available in either white or black and cost $649 for the 16GB model and $749 for 32GB model.

An unlocked iPhone 4 is a GSM-compatible iPhone 4 that is not contractually tied to any specific wireless carrier and can be used on any compatible GSM network. (Click here for more about GSM.)