The insperation for the Junkbots project came from reading the seminal book Junkbots, Bugbots, and Bots on Wheels by Dave Hrynkiw and Mark W Tilden. In this book they discussed turning electrical 'junk' into some very interesting robots - and sneaking in some very interesting engineering challenges and principles. A sample chapter can be found here looking at producing a solar powered motored 'bug'. The robots built within the JunkBots project are simpler but the principles are the same. If you are interested in this area this book is a must read.
This is an initiative to mix sustainability, engineering and computing to students.