Unlocked iPhone 4

 iPhone fans may not need to resort to extreme actions to unlock their phones much longer.

 The Apple rumor mill is grinding away already this week, with a report that an unlocked iPhone 4 will become an option for U.S. customers in Apple stores on Wednesday.

 The rumor comes courtesy of Twitter user @chronicwire, who apparently set up the account about a week ago and quickly started tweeting all kinds of purported iPhone leaks and rumors. The latest is that four specific models--the MC603 (16GB, black) MC604 (16GB, white) MC605 (32GB, black) and MC606 (32GB, white)--have already landed unlocked and retail-ready on U.S. shores.

 I've seen reports claiming that @chronicwire is a "well-known source" and that the unlocked iPhone rumor is considered "certain," but haven't been able to divine the basis for either, especially for a source that apparently materialized from thin air a week ago.

 It should also be noted that @chronicwire has been changing his or her story lately, intitially reporting that Apple would be announcing a MacBook Air refresh for back to school on Wednesday.

 Nonetheless, the notion of an unlocked iPhone being sold in Apple stores isn't unprecedented.

 Unlocked iPhones are available in Canada and some European countries, among others, but have never been sold in American Apple stores. It's likely that the unlocked phones--if it's true that they are headed here--would only work on GSM carriers, which means only AT&T and T-Mobile among the major U.S. carriers. So, the real beneficiaries of an unlocked iPhone in the long run--especially if the T-Mobile/AT&T merger goes through, further reducing the number of GSM carriers--are international travelers, who could more easily swap out their SIM and use their unlocked iPhone with local carriers in Europe and elsewhere.

 An unlocked iPhone wouldn't be great news for AT&T, which loves to promote itself as the best option for international travelers, but many AT&T customers have had a rude awakening when the bill arrives following a trip abroad. So here's hoping mystery-man @chronicwire knows what he's talking about