DavidB let me know about this thread on PinStack where AZstar noticed this cool looking waterproof floating Bluetooth speakers. They provide stereo sound over Bluetooth using AA batteries and even have a remote control built into them so you have play, pause, volume control, and next/previous track control. It pauses when you get a phone call but sadly you will not be able to speak or answer the call from the speaker.
The speaker even floats so you can have it floating around with you in the pool or just carry it into the shower. I have been looking for a solution like this for awhile and at $40 from ChinaVision I will definitely be checking it out!