If you run your own GSM network (ie: OpenBSC/OpenBTS), you don't even have to "unlock" your phone. You can just allow your simcard in the HLR database and restrict everyone else from joining your "cell tower".
Oh sh**... didn't look at the thread date...
Don't worry.. It was bumped by a spammer to whom I replied to with an appropriatly terse response, only for the mods to remove the spam post making it look like I bumped it back from the grave. Honest guv it wasn't me.
Kudos to the new mods for dealing with abuse so quickly