With Dada's Code M, you can listen to music played from your shoes. From the website:
... the Code M system is integrated into the shoe's heel and tongue. Its memory gives the device the ability to hold up to 100 songs with a six-hour battery life... Another important element in the system is the wirelss headset, which picks up music from the shoes as far away as 30 feet. Consumers will thus be able to hear musical choices while wearing the shoes, as well as after removing them so long as they stay within a 30-foot radius of the shoes.