As soon as the iPhone was released, the geeks were off to the races to provide the best possible unlock for the best-selling handset.

A group called iUnlock may have bested its competition by releasing the first free, open-source iPhone SIM unlock application. Written by the iPhone Dev Team, the hack isn't for the techie faint-of-heart, but works with the latest versions of iTunes and the iPhone firmware.

According to Engadget, the user will need the iUnlock, nor and .fls files (the iUnlock application can be downloaded from here. The official installation guide can be found here while the unofficial guide can be found here.

Keep in mind that this is essentially "caveat emptor" and while the hack has been confirmed, be careful. A member within the development team has confirmed that an application to achieve this should be out "very soon" to make the unlock easier for new users.

Also, depending on the activation method, YouTube might or might not be functional after the unlock.

Like most programs and techniques that are still being developed, good luck and be careful.

If you've tried the unlock or have an opinion about this, let us know in the comments or forums.