The latest iPhone rumors say Apple will start selling unlocked iPhone 4 starting Wednesday. A source is a Twitter user called @chronicwire who, according to tech sites, has made true predictions in the past.

Why would Apple sell unlocked iPhone 4 at this point, which will be the first time it's doing in the US? A buyer of unlocked iPhone would want to use it on networks other than At&T and Verizon which already offer iPhone on their networks.

According to the leak four unlocked models of the iPhone, the MC603 (16GB, black) MC604 (16GB, white) MC605 (32GB, black) and MC606 (32GB, white), will be on sale starting Wednesday.

Another hot rumor doing the rounds these days is that Sprint could soon feature iPhone on its network. Various media reports have said Sprint is testing a version of Apple’s iPhone for its network.

There is another development related to the whole thing. It is said At&T is eying to buy T-Mobile. If AT&T succeeds in acquiring T-Mobile for $39 billion in cash and stock, it would make Sprint the only carrier in this country without Apple’s bestselling smartphone in its portfolio, according to eWeek.com.

And then, if Sprint is also jumping on the iPhone bandwagon, what exactly will be the use of an unlocked iPhone? People used to buy unlocked phones so they could easily hop from carrier to carrier. But is this relevant anymore now?

CNET says the unlocked iPhone will be appealing only to the international travelers. And in this case, it would a letdown for AT &T, which is known for the focus on this segment of users.

However, it has been pointed out that the releasing of unlocked iPhones will not be exactly an unprecedented move. Unlocked iPhones have been on sale in Europe and Canada in the past.