The Smothers Brothers has anounced a concept MP3 player. Those yo-yoing freaks would never need batteries or a charger.
The REGEN MP3 player on the yo-yo is powered by yo-yoing. 10 or 12 yo-yo tosses per hour are enough to keep your music running non-stop. Thinks it’s impossible? No, Bluetooth wireless headphones are included for you.

The concept MP3 player has capacity for about 200 songs, and is simple to use.