Both are based on ideas from Tonuino, an open source project aimed at turning Arduinos into MP3 players.

A cool RFID music table has been created using Arduino, iPod, and RFID tags to make it easy to change albums by simply changing the RFID tag.

Instructables user talk2bruce created the Arduino Internet Gizmo, a card reader that takes you to your favorite websites with a touch of an RFID tag.