MP3 Player

I've been searching for an mp3 player that is useful for schools. This would be 1) cheap, 2) just an mp3 player, 3) somewhat sturdy.
See here's the problem. I can see a teacher using an mp3 player to record directions, record primary sources, and more. But that teacher would need several mp3 players to hand out. Thus, it must be easy to load material onto multiple mp3 players. (And we're not talking copyrighted stuff here).
Next, when kids use it, they don't need to be able to listen to FM radio or use a voice record function. (Working in a middle school, the ability for kids to record voice messages for each other could be, oh, let's say, a distraction.) Thus, I would like to find an mp3 player that doesn't have any "bells or whistles".

So while I've found lots of mp3 players at $20 (a reasonable price), I haven't found one that doesn't include any extras.

How would you use an mp3 player as a teacher?