The Fly on the Ceiling by Julie Glass

Recognized as the father of analytic geometry, René Descartes was a French mathematician and philosopher. Kids will love this funny and very accessible tale - based on one of math's greatest myths - about the man who popularized the Cartesion system of coordinates.
Here is a lesson to introduce and work with kids on a system of coordinates - http://www.uen.org/Lessonplan/preview.cgi?LPid=11237  Here is some background on Descartes - http://mathforum.org/cgraph/history/fly.html