I was having trouble at my drawing course (I'm really crappy at drawing) so I figured out, why not use my shapeoko to draw?
I made a simple pen holder in the place of the dremel, and decided to use half-tones to render images. For this, I downloaded the very cool Scriptographer plugin for Illustrator. It allows you (using the Object Raster script) to do an half-tone version of any images using any vector graphic you want!
To convert this to g-code, I tried to used pycam but it was way to slow. So I used the great 2.5D gcode creator Partkam. It supports SVG and works no matter which OS you use since it's Flash! With the "follow path" setting I was able to draw my Illustrator file.
(sorry for the crappy quality, I don't have a camera so I had to do it with Photobooth)