dive into mark: Cantor sets and The infinite hotel. The articles are interesting, and so are the discussions that follow. Someone mentions the Hausdorff dimension (scroll almost all the way down the first discussion); Felix Hausdorff was a mathematician at the University of Bonn. He was Jewish and committed suicide in 1942 when the Nazis tried to send him to an internment camp. Before the summer holidays, I did a project about him with two other teachers and about 30 15 year-old students. They were very interested in his mathematical works but also in the poems he wrote. Hausdorff is buried on one of Bonn’s cemeteries.
Also worth a look: Hypotenews, a publication produced by A level math students at Farnborough Sixth Form College.
And a MetaFilter thread about Hotel Infinity.