How To Really And Fully Wipe A Hard Drive?

root_dev_X ventures: "Admittedly, this is a random question, but here goes - Does anyone out there know of any ways to totally erase the data on a drive? Some friends of mine got into a discussion about this not too long ago; one of them told me they had heard from a friend in the military that they hooked up old HDDs to modified stun-guns and zapped them in order to totally erase them - apparently this method scrambled the magnetic field of the disk, leaving the data irrecoverable. Does this work? Are there any other methods for "data-destruction" (keeping the platter intact, that is)?" A nice "obliberate data to the point of senselessness" tool would be nice -- or is keeping the platter intact a senseless question if you want true security?