completely erase data

My company has some laptops its going to donate. There pretty nice. 80gb hard drives. Problem is SOX requires us to completly remove ALL Data so it doesn't and can't be recovered.

So I'm looking for a way to do it. Something as simple as a boot cd that will erase all data and prevent it from being recovered.

Problem is, my company doesn't like to spend money. SO I have to find a free solution. Anyone know of any good ones. Just something that will erase all data and prevent it from being recovered but also allow us to reuse the hard drive.

Please Assist.

AutoClave
Active@ KillDisk Free Edition
Darik's Boot and Nuke
PC INSPECTOR e-maxx

are all free they come on the ultimatebootcd, but you can find their sites.

To save you from the googling, here's the same list, plus one new program, that oofki just posted but with links:

Autoclave
Active@ KillDisk
Darik's Boot and Nuke
PC INSPECTOR e-maxx
Eraser

Ultimate Boot CD