When I was trying to sort out a virus, I downloaded Seagate Tools, which is designed to fit on two floppys. This will format a HD back to square one, I think. Even the partitions disappear.
It works on Seagate, and after a warning, on Quantum HDs, both >40gig. Haven't tried it on anything else. It takes about an hour to do the job.

Not really helpful to SRSage, but maybe to others.