I made this charger whill on my bed just playing with a USB cable then an idea hit me this is how to make it:
Usb cable extender( The thing with the female and male plug on it)
Battery Holder it must hold 3 AA battreis( you can find them inside some torches)
And 4 AA batterys ( one for spare)
Step 1: Cut It
Now cut the female plug( the one that plugs into your computer) off and strip the wire. Now to find the - and + cables inside the usb extender, put one on your toung (DON'T WORRY IT WILL ONLY TINGLE NOT SHOCK AS IT IS DC CURRENT) and then touch the other ones. Norrmaly it is black and red so test those ones first.
Step 2: Connect It
Now take the two and connect them to a full battery holder. To test if you have it the write way plug in something that will indercate it(e.g a usb stick with a light) If it lights up then tape it to the battery holder. Now find a nice cover or thing to put it in. There are normally 4 wires from the usb cut the other 2 off and place tape around the exposed bit.
Step 3: Plug In
Now you can plug in an iPod shuffle( I cant seem to get it to work with other iPods but i will test it tommorow with an iPhone)
And watvh it work :)
In the picture is a little light i made with the rest of the tourch i broke. It is connected to the male plug.
I placed the little light in the iPod shuffle box ;)