 
       
How to make an ultra-simple iPad stylus. The materials are a metal pipe, a screw, and conductive sponge.
 
Wrap the screw with the conductive sponge.
 
Insert it into the pipe. Done. The pipe should be around 7mm, but you can adjust it to your preference. I used an aluminum one. After this, shaping the sponge with scissors improves usability.