There is still no way to unlock a BB5 Nokia by code generator (6630,6680,N70,N80 etc.). Not even nokia themselves have a code algorithm for these models. The main man in the mobile phone world is still working on his software for these models and is not nearing completion anytime soon.
Do not buy these fake code calculators claiming to be the real thing, because you may hard lock your phone if you enter the wrong code a couple of times.
Ebayers offering codes for cetain models on certain networks (eg 6680 on Vodafone) for around £30 are more often than not genuine and themselves working with/for the network in question (They have access to the networks code database).
If you really don't want to send your phone in the post to get it unlocked (usually around £10 and the best way in my opinion), Then contact your network and pay them for the unlock code direct.
If in doubt, Check feedback!!