Why is Apple (finally) offering an unlocked iPhone 4?

Unlocked iPhone 4 handsets went on sale at the US Apple Store website today, and the prices certainly aren't cheap – $649 for the 16GB model, and $749 for the 32GB model. (With a two-year contract, iPhones usually cost $199 and $299.) Black or white. Take your pick. The handsets allow users to tap into any GSM network, which means frequent travelers can now use local carriers when traveling abroad, instead of running up data and voice service fees on foreign networks.

In addition, an unlocked iPhone allows users to opt out of a multi-year contract; the trade-off, according to Computerworld, is that you won't always get a 3G connection. (Instead, you'll get the older EDGE connection.)

Apple, of course, has long sold unlocked phones in plenty of other markets, including Europe, but held off on an US edition. So what prompted the about face? Over at PC World, Sascha Segan evaluates some of the possibilities: The unlocked iPhone is a clear attempt to appeal to international travelers. Apple is trying to make the FCC happy. Or perhaps "Apple has nothing to lose."

But the best answer may be the simplest: A new iPhone is on the way, probably in September. There are three long months between now and September – long months where Apple could see interest in the outgoing iPhone 4 start to fade. By stirring up a minor press flurry around an unlocked iPhone, Apple can keep general iPhone buzz high, gin up a few sales, and generally hold off against incursions from Team Android for as long as possible.

Then again, maybe we're a little conspiratorially-minded these days. What we do know is this: The iPhone 5 is almost definitely on the way. As we noted yesterday, several "high level Apple and carrier executives" have been spotted carrying around iPhone 5 handsets – caveat: the device could be called the iPhone 4S – and Apple is rumored to be entered the final round of testing for its forthcoming smartphone.

Interested in the unlocked iPhone? Drop us a line. We're listening.