I really enjoyed this, thought you would too.
Sine Waves:

Synth and Distortion:

There is a description and more videos here:  http://www.dima-vj.com/lissajous/liss_Eng.html
- Kuba

Awesome. Very inspiring. Would be great to have one of these.

Step by step: http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/ 
Some parts: http://www.unistrut.com/