After reading Remove Sensitive Data Before You Sell an Old PC , Joel Edillon wants to know if it's a good idea to physically destroy a hard drive instead of wiping it with special software.
I wouldn't advise it. Who knows what sort of toxins you'd release into your living room by throwing a hard drive into the fireplace. I've heard of people smashing them with a hammer, but I'm not sure that would stop a really determined data thief.
Besides, hard drives have value, and if you don't want this one, someone else will. For instance, your county's recycling center would probably rather have a PC with a hard drive than one without one.
Another option is to have the drive degaussed. Basically, someone runs a very powerful magnet over the drive, wiping it clean. There are services that do this, but it's barely practical unless you're a huge organization with lots of drives. My local recycling center ships drives to a degaussing service, but they charge $25 per drive for the service, and you don't get the drive back.
Destroying the data with software, as I recommended in the earlier article, really is the easiest and cheapest way.