I was wondering why no mention of CMRR was made? although it can be a little hard to use, I have found that it can do a drive in less than an hour. be sure and read the white paper. i mostly used on laptops and would keep the program running in memory and simply would pop the drive in that i wanted to wipe and hit one button and usually in less than 40 min i had a "ABOVE DOD" wiped drive (read the white paper) by the way this is a free program

http://cmrr.ucsd.edu/people/Hughes/SecureErase.shtml

The other good news is this was a university project to design this program, reading the history of its creation and goal of wiping a drive in as much the same way if you had ran a steam roller over it yet still be able to re purpose the drive. The other programs are nice and graphical easy to use and I even use one or two of them for cleaning thumb drives and folders ???..CMRR on the other hand is HARD CORE in a short amount of time ???so if you are in network operations and you are trying to stay on a schedule because you have a million other things to do (all network/server admins are like this) time and doing the job correctly are the name of the game???..Protect the data ? that means destroying it also!