Though there's no shortage of places to buy an unlocked iPhone, I haven't seen many wireless stores that specialize in selling them. But last weekend, I came across a store in San Francisco's Civic Center (corner of Larkin and Golden Gate) that does just that. Not only will the store sell you an unlocked iPhone with the activation of a new T-Mobile account--all for just $299--but also it will unlock your current AT&T iPhone for you. Since it was Saturday and the day after Independence Day the store was closed, so I didn't get the opportunity to inquire about how many unlocked iPhones they sell. But I would imagine they do a decent business.