I've seen this here before, but I had to try it myself. I had a lot of bad 'drawings' since its hard to see what your doing when turning on and off a laser and writing on something that doesn't show what your doing (such as a wall). I'll try to see what I can do with some more time and better creativity.
This was done with my DIY red Senkat Diode laser.
This was done with my DIY red Senkat Diode laser.