If you're only using it for music and/or audio cues, another option is a waterproofed iPod Shuffle. Wouldn't cost you any more than a quality waterproof box and handlebar mount.

I have one from Underwater Audio that I use for deep water running. So it's actually submerged during my workouts. Works great.

I'm all about listening to my body and getting inspiration from my surroundings, I'm very strongly against music during outdoor running, but there is no way I would be able to keep up my cadence or avoid going out of my mind with boredom, going back and forth in the pool for an hour and a half at 4-5 minutes per lap without music.