Chevron WP7 has been working on an app that would let you legally and without breaking your warranty “sideload” applications. While this is not quite an unlock for the price tag of nine dollars you really can’t beat it.
So what is sideloading? Sideloading is the ability to install apps not in the official windows apps store. While this does not make a Nokia Windows Phones as open as Symbian Phone it is a step in the right direction.
For more info on this app you can check out the