Bernoulli blowers
Screaming balloon
Hinged mirror reflections - the angle of the mirror determines the number of reflections that you see - the bigger the angle, the less reflections; the smaller the angle, the more reflections
3-d glasses and a geyser
Fun with photo booth
The video on the right was from a heat camera.
OscylinderScope
Wave machine and Resonant rings
Resonant Rods and Gaussian Melody
Giant slinky waves
Image relay
Drawing table