According to the hacker-proprietor of Teravolt.org, shining a 250 mW green laser through a hanging drop of scummy plant water produces a kind of “laser microscope” that will project shadows of all the little microflora on the wall so you can watch them flitter about with the naked eye. The embedded video is nothing short of amazing. I felt just like that cat.
Anybody out there ever tried this with a blue or violet laser? Is the resolution any better?