Slag your drives to thwart data recovery
A recent MIT study of 129 used hard drives indicated that people leave a treasure trove of data behind on their discarded computers.
This begs the question of how can you securely dispose of old hard drives? Well, the typical answers are to use a secure wiping program or degaussing, but these are not 100% effective.
Some people have come up with a foolproof method called Drive Slagging which involves melting down the platters and essentially creating aluminum ingots.
Not exactly do-it-yourself though :-)