Low Resource Distro and Window Manager for Kids?

Philljd asks: "Computers 4 Kids is an organization run by the IT &amp ;CS department of Wollongong University in Australia that picks up computers from the local area, installs Linux on them and gives them to needy kids. We want to know what Slashdot readers think would be the best choice of distribution and window manager for an average system spec of a Pentium 100, given that the kids are around 10-13."