I built myself a homemade stylus--a pen-like device for drawing, writing, or interacting with a touch pad (like iPad or iPod). You can find the instructions here if you'd like to make one yourself. Here's how it works. As long as you're holding onto the paperclip, your body's natural electrical field transfers the energy into the (damp) sponge and registers on the touch pad. The pen, sponge and paperclip by themselves don't make a difference--you need all of the parts working together. So there you go--a little science in support of your doodling. Have fun!