An interesting impromptu project: a laser pointer directed through a drop of water projects a large magnified image on the wall.
Teravolt.org – Laser Microscope.
This reminded me of the setup that Gabor described decades ago for inline digital holography. I might have to give this a try sometime.
httpv://www.youtube.com/watch?v=2aK_a-jr-tI
Holy crap, it works! I just tried it with a green 5 mW laser pointer and the wash-bottle I use to wet my soldering iron sponge. Gotta make me a better lash-up and take some pictures/video.