For Justin, Ian and others who might be interested in hyperspace, and superstrings.
In an article by Saul-Paul Sirag `Notes on Hyperspace' (found somewhere on Michio Kaku's website), there are references to HMS Coxeter. Here are some of his books:
Introduction to Geometry, Wiley, NY, 1969 Regular Polytopes, Dover, 1973 Regular Complex Polytopes, 2an Ed, Cambridge, 1991
The last, Regular Complex Polytopes is flat out one of the most beautiful math books around. It is easy to why there might such an asethetic appeal for higher dimensional complex hyperspaces, whether these can be shown to have physical significance or not.
In any event, for anyone who wants to learn more about spatial symmetries and discover their unbelievably prodigious abilities to open entire realms of mathematics in a few strokes, check out Coxeter.
Chuck Grimes