Hmmm, I think I would be too afraid to use headphones due to the risk of lice n' stuff.Oh, that's easy. Get any MP3 player (handheld device, PC, or whatever) and a pair of headphones, maybe two with a splitter. I think teams really enjoy AV stations because they're changes of pace; I ran one at State last season for a different event, and the results were fantastic. I have, in the past, done the "demo" station John noted with sets of speakers, but I'm less fond of that set-up. You're at the mercy of the acoustics of the room.
...Afraid to use headphones from an ES perspective, that is. As a competitor, I would just shut up and put on the headphones and win.