I've worked with a band that has a couple of them cheap red and green laser effects that you could get at GC. I just got in a couple $15 Chinese ones that do this:
I seem to remember that the GC ones did more patterns but they were close to $100 each I think. Anyways the Chinese ones are labeled as class IIIb and maybe require a variance to legally use? The ad I bought them from said that both lasers are 50mw although the "manual" that came with them says the red is 100mw and the green is 50mw. The beams are always split many ways so I doubt any one beam is over 1mw. They seem to work OK - the green is much brighter to my eye than the red but I think that's because of the way our eyes respond to different wavelengths. Whatcha think about all that?