This site might interest you. Its a product review, a strip of some sort which goes where some of the pins goes to unlock the multiplier
Thats the only way I know how to. Can't seem to find any sites either. I know you can unlock the Athlon XP processors with a pencil, but not the 64 models unless you use something as far as I know.
I've heard the FX models are unlocked, and so is the 4000+ 64 model, and the Mobile chips