Of course, I always demag my CDs and DVDs before use! The Tourmaline Negative Ion effect really does wonders too. And I think you will find this interesting: "Manufacturers had realized that demagnetization enhanced the capability of Software." I made sure to demagnetize my Cubase installation disc before reinstalling it on my new computer recently; now I can use twice as many effects, I haven't even found my track limit, and everything just sounds better!
This got me thinking, and lately I've been working on a way to demagnetize my car's fuel injection system to increase MPG and save money on gas!