I always use Eraser - if you just do a search for "eraser" on download.com you can get version 4.7. It's the best shredder ever - has Guttman built in which is 35 whipes.
But in all actuality there's absolutely no way to destroy all traces of data - the only way to destroy it to where it can never ever ever be recovered in the history of timeis to break the drive in to 1000000 pieces and sprinkle it in the ocean.
Otherwise there's always a way - even if you burn a drive or dip it in acid- Magnets are insane huh?
New PC (Finished May 4, 2004)
Athlon XP 2800+
Soyo Dragon ultra Platinum KT600
1024 MB Kingston Hyper-X
120GB 7200 RPM 8MB
160GB 7200 RPM 2MB
GeForce FX5500 256MB
16x52x32x52 DVD/CDRW Combo