Unlocked iPhone 4: Now In The Apple Store Starting At $649

Apple is officially selling unlocked iPhone 4 models.

Visitors at the online Apple Store can select from a 16GB unit for $649 or a 32GB unit for $749. Customers can choose from either white or black flavors.

Available only in the U.S., the unlocked devices are GSM-compatible, meaning users can place calls on either AT&T's network or T-Mobile's without having to sign a two-year contract for either carrier. The catch, however, is that the unlocked iPhone won't support T-Mobile 3G download speeds.

"[D]ata transmission on the T-Mobile network will occur over the slower EDGE protocol because the carrier's 3G network is incompatible with the iPhone," Apple Insider points out.

Could this offer possibly be a precursor to a full-fledged T-Mobile iPhone? CNET implies so:

Earlier this year, AT&T announced its plans to acquire T-Mobile USA from Deutsche Telekom for $39 billion. If that deal is approved by regulators in the coming months, there will be just one GSM carrier in the U.S., and the need for an unlocked iPhone 4 will be diminished.

For now, Apple bills the unlocked device as an ideal companion on trips overseas.

"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," Apple's description of the device reads. "It arrives without a micro-SIM card, so you'll need an active micro-SIM card from any supported GSM carrier worldwide."

This could mean cheaper rates for U.S. iPhone users who make calls while outside the U.S.--great news for vacationers who rack up massive phone bills by placing calls on local networks in foreign countries.

However, Technologizer sheds light on another crucial caveat: an unlocked device costs about $450 more per year than a locked version with a two-year contract.

"Here's how the total cost breaks down, assuming you choose the cheapest voice and data options and stick with AT&T for two years," writes Technologizer. "Locked AT&T iPhone 4 minimum cost: $1758.76 ($199 for a 16GB phone, plus two years of voice and data at $64.99 a month) [...] Unlocked iPhone 4 minimum cost: $2208.76 ($649 for a 16GB phone, plus two years of voice and data at $64.99 a month)."

If you don't take your iPhone on frequent trips outside the U.S., an unlocked device might not be the best choice for you. But if you're a frequent flyer fed up with high roaming charges, then you might want to consider Apple's offer.

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