I had the idea of making a pointing device shaped like a pen, so I combined a mouse with a wooden stick. It was messed up, but much better at drawing pictures!
What you need:
Cheap mouse (any kind will do)
Take the mouse apart. There are usually little screws on the bottom. If you take all the screws out and it still doesn''t come apart, look under the stickers. Leave the circuits on. Just take the top off.