Here's a video of my laser spirograph in action. It's just three pc fans with mirrors attached to each fan and a potentiometer to control each one and it's all stuck on a piece of wood. I might build a spiro in a project box with a few more bells and whistles but this was cheap and easy.
http://www.youtube.com/watch?v=HQvi0mjknKQ
http://www.youtube.com/watch?v=HQvi0mjknKQ