Drawdino

Leah Buechley brought up a great idea about using graphite pencils tied with an Arduino. There is a site devoted to Drawing + Arduinos called DRAWDINO. It's really fun what they're doing with making music and drawing circuits:

http://web.media.mit.edu/~silver/drawdio/

Electroluminescent Ink

Link to a video on a demo of electroluminescent ink on Vimeo