Via The Wepben Blog check out Dictionaraoke; 100 songs as sung by pronunciation tools.
Somebody has had a lot of time on their hands. My personal favourite was Depeche Mode's Enjoy the Silence, but then that is one of my favourite songs of all time anyway. The best one that everyone knows was probably Anarchy in the UK.
Via Fetch Me My Axe, check out The Angry White Boy Polka (although persons with more refined musical taste are unlikely to know any of the performers there satirised).
Finally, try your hand at forging a Jackson Pollock - may not be as hard as you always imagined. That was a random find.
If you notice anything odd happening to my fonts, this is because I have been reading a book all about CSS (uh... Cascading Style Sheets) and now think I can transform my template without any glitches. All digits crossed.