Here below is a photo capture of this effect, at times the effect darts off onto the wall 90degrees from the screen. It is very impressive!. It has not and cannot come back at me from while watching, it is safe to do this though I would recomend that it is not setup in an area where other people might bump into the setup and upset the beam path from the intended direction.
I have made a metacafe video showing it in operation
Disclaimer: There is a danger of being exposed excessively to laser radiation as with any laser project, yet the beam/effect has never done a 180 turn and come back at me in the viewing area. I would assume this would be attempted by responsible knowledgeable persons who are fully aware of the dangers of experimenting with lasers.
I had been accumulating all my dead lighters for quite a bit of time with no idea what I would be doing with them till I happened to notice these very cool patterns reflected by my laser from certain types of plastics. I found that the green and blue (blue is best) gave some noticeable patterns. Look at the blue lighter! I have been using it for some time now and it is full of "laserpit" gouges from the beam!