Sparkfun Electronics Sparkfun MP3 Player Shield

The Sparkfun MP3 Player Shield is an MP3 decoder with the capabilities of storing music files onto a run-of-the-mill microSD card, thus giving you the ability to add music or sound effects to any project. With this board you can pull MP3 files from a microSD card and play them using only one shield, effectively turning any Arduino into a fully functional stand-alone MP3 player.