True dkw, that's what I've always done when I sold my PC's - Smash the HDD, and buy a new one or tell the one you are selling it to that it has no HDD atm, price will drop a bit but it's worth it and you don't have to worry at all.
What happened to that thread where we gave scores to people's avatars? I remember being very hard on PloKoon's when it first appeared, and I've now grown quite fond of it! Familiarity can breed affection!