We've all seen the reports - if you're not careful with your drives, sensitive data on it can be recovered by thieves when its chucked out. Hammers, explosives, etc won't do it. So what do you do? Well how about slagging it? A couple of people have figured that by melting down the aluminium contained within the drive platters, it would (a) convert it from a readable disk into any shape you pour the molten aluminium into, and (b) nullify the magnetic properties of the metal. All you need is a furnace designed to melt down aluminium and other metals!