I've wanted an infrared camera for years now, so I wrote a grant a year for a simple Flir camera that attaches to your phone (approx $425.)  It's really cool and it has opened student's eyes and has helped them get a better grasp on the electromagnetic spectrum.  Frankly, I kind of can't believe these camera's aren't standard equipment for all science departments.  

Class photo, Project Based Science

Henry and Jenny stand in front of 2 identical looking beakers. Which conatins the hot water?

Hot water on the left, cold water on the right.

How many fingers is Mike holding up inside the bag?

Three!

Half of Joe's face is behind window glass.

This demonstrates how infrared light does not travel through glass.