Hmm, I'm not sure about this, but I was once told that HD platters are slighty radioactive. Something to do with the way they are manufactured. Now, I realise someone was probably pulling my leg, but you never know. :-)
I don't have a creative story about destroying a HD, but I have always wanted to remove the platters, use a grinder and file to create the perfect Ninja star. I have to admit though, this is a fantasy I only have when I have spent a weekend on the couch, over endulging in old Ninja and Samuri films. :-P
Xamiche