First you need
2 sweet potatoes,
2 copper wires,
2 new nails,
and your MP3 player.
1) poke one nail into each sweet potatoe.
2) Tied one end of the each copper wire to one potatoes.
3) Tie the other end of one copper wire to positive side of your mp3 player, where you use to put in your battery.
4) Tie the other end of the oter copper wire to the negative side.
5)
Switch on your MP3 player.http://futtech.blogspot.com/2007/07/potatoes-power-my-mp3-player-amazing.html