Today's freeware pick comes in the form of a secure hard drive erase tool for windows users.

"Darik's Boot and Nuke ("DBAN") is a self-contained boot disk that securely wipes the hard disks of most computers. DBAN will automatically and completely delete the contents of any hard disk that it can detect. "

More info and a download link can be found by visiting http://dban.sourceforge.net/