Thought it would be a cool thing to do, easy too. If you want to do it, all you need is an old pair of headphones and speaker(s). I just found some old spaekers i got from an old PC, a big one and a small one. They have two wires, one being positive and one negative (black and red). Cut out the metal jack from headphones and shave off the plastic. There are two terminals on the jack, that's just a piece of medel. One is right at the base of the jack, right where the palstic starts, and the other is at the end of jack (thats in the plastic). Solder (or glue) either a red or black wires to each. That's how I made mine. It worked.
Its cool if you want to make a portable speaker thing that you can plug an Ipod into, and it doesn't need extra batteries ( probably uses a lot of electricity from the mp3 player or iPod though)