Galileoscope
Each committee should have received a box which contain 6 Galileoscopes in September of 2010. These are small telescopes which come DISASSEMBLED so the girls can learn about OPTICS while they put them together. You can leave one of them in pieces so show the process, take them all apart each time, the choice is yours.
There is a PDF of the Girl Scout and OSA collaboration book- Lighten up! which also has additional programs on optics for all ages.
https://www.galileoscope.org/gs/content/downloads (original link)
http://www.uwyo.edu/caper/info.asp?p=16091 (additional downloads)
Forms you can use: