I'm too scared to turn on my CD player or Nintendo DS on planes. I'm always afraid they'll interfere on the airplane instruments. Well, a passenger speaking in a cell phone while a plane was taking off caused it to activate the flaps or something like that and caused a major plane crash in Sao Paulo, Brazil, in 1996. Since then it is forbidden to turn it on while in a plane. So I don't take any chances. I rather read a book, read those in-flight magazines, or watch the in-flight movie: "Alive", "Final Destination", "Airport", and "The Buddy Holly Story".