Here are some more paper toys you can build. The Spectrum Snail is very cool. If your a science teacher or have kids and you want to give them a simple demo of how white light is made up of differnt colors, this would be pretty nifty. The paper DNA is also very cool. Cerative use of old PET plastic bottles too!
CD Spectrum Snail – Spectrascope made out of a CD and paper
Paper DNA Model