Sony sells its waterproof mp3 player inside a bottle of water 
I'll hand it to Sony, they can come up with some sweet marketing campaigns.On a side note, do a lot of people really listen to music while swimming?  In college I used to do 30 minutes of laps in the pool a couple times a week.  I liked doing it precisely because you couldn't listen to music and you'd have to focus on keeping good form.  It was just you and the water.