Listen to 808s while doing your laps with the Speedo Aquabeat by iRiver ($135 - $150). This compact design features a waterproof housing that floats and safe to use in depth of up to 3 meters. It comes with a waterproof earplugs and ergonomic buttons easy enough to navigate while gliding in water. Aquabeat can play for 9 hours fully-charged and is compatible with iTunes and Windows Media Player.