T-Mobile USA is now specifically targeting unlocked iPhones on its website by offering Micro-SIMs that are compatible with the officially, and unofficially, unlocked versions of Apple’s GSM iPhone, reports Appadvice. The iPhone is an exclusive to AT&T in the US, so T-Mobile has not been able to overtly court these users.

Now that Apple is offering unlocked versions of the GSM iPhone directly from its website for $649, T-Mobile is able to directly market these SIMs to iPhone users without getting heat from Apple or AT&T.

Already have a GSM phone or iPhone that you need to activate – or have an unlocked GSM phone you want to use on the T-Mobile network? Just get a Micro SIM card and choose a plan. Slip the ready-to-use Micro SIM Card into your phone and you’re ready to go.

T Mobile SIM card front and back 642x580 520x469 T Mobile courts iPads and unlocked iPhones with Micro SIMs

These Micro-SIMs can also be used in the GSM models of iPad and iPad 2, also technically AT&T exclusives. iPads are not locked to a carrier though, and a simple carrier settings change will enable them to work on T-Mobile just fine, albeit at slower 2G speeds.

The Micro-SIMs are offered on T-Mobile’s website for free, but are tied into a 2-year contract. This makes them technically a worse deal for iPad users as AT&T offers a no-contract data plan. If, however, AT&T service in your area is terrible or nonexistent, this does provide you with another option for an unlocked iPhone.

iPhone owners have been unlocking the iPhone since 2007 for use on T-Mobile’s network via unofficial unlocking tools available on jailbroken devices. T-Mobile currently carries over 1 million unlocked iPhones on its network.

As always, rumors of the iPhone coming to T-Mobile persist, but it is unlikely that we will see any additional US carriers this year. Apple is launching a new iPhone model this fall on the two largest (by far) carriers in the states and I think that T-Mobile will have to remain an alternative for unlocked iPhone users for now.