Fairy tale of OpenSource
Yutaka Kachi have made a very intersting slides explaining the open source movement and comparing software to a fruit tree. He explains the motivation and process of open source projects on a level that even a child could understand. The slides are available in PDF in three parts, Parts 2 and 3 get into the different lisences. If you are looking to explain the open source movement for kids you can't find more easy to use material than this one. The slides are available under a Creative Commons License.
