CNN.com - Music students learn the art of the scratch - Feb. 18, 2004
I was interested in this article, simply because I'm interested in the skill. It's a fascinating art form, physical movement to combine songs or sounds together. It's also just plain fun to hear the music.
The one thing not mentioned is his book -- which doesn't appear to be popular with the kids on Amazon... but may be worth a read in a slightly less expensive edition.