This is the world's cheapest laser light show... It converts your voice and sounds to laser patterns. I made the first one years ago with my dad. We simplified the the design for BurningMan2006. We helped 200 people in one day make them at MakerFair 2007. TechShop was kind enough to supply the materials and booth space.
-Tube (at least 4in long, between 2 and 4in in diameter)
-Laser pointer (like the cheap ones from longs)
-A latex glove or balloon
-Coat hanger (or ~12in piece of welding rod, best for mass production)
-Hot melt (or double sticky tape, safer to handle but more expensive)
-Drill w/ small drill bit (size of the wire or coat hanger)
-Vice grippes or pliers
Step 1: Bend the wire
Bend your wire or coat hanger in half with small chanel down the center and bend the ends up in the same direction.