Devices including iPods and Zunes can be hidden under clothing, with just an earbud and a wire snaking behind an ear and into a shirt collar to give them away, school officials say.
''It doesn't take long to get out of the loop with teenagers,'' said Mountain View High School Principal Aaron Maybon. ''They come up with new and creative ways to cheat pretty fast.''
Mountain View recently enacted a ban on digital media players after school officials realized some students were downloading formulas and other material onto the players.
''A teacher overheard a couple of kids talking about it,'' said Maybon.
Shana Kemp, spokeswoman for the National Association of Secondary School Principals, said she does not have hard statistics on the phenomenon but said it is not unusual for schools to ban digital media players.
''I think it is becoming a national trend,'' she said. ''We hope that each district will have a policy in place for technology—it keeps a lot of the problems down.''
My friend was caught cheating from an iPOD and lost his iPod to the supervisor which in turn gave it to the principal. 
