Continuing my theme of slightly interrelated random stuff or as ninad commented "completely interesting but completely pointless stuff" I'd like to talk more about A. K. Dewdney. I mentioned A. K. Dewdney Earlier as the author of The Planiverse . In addition to The Planiverse Dewdney has written another of my favorite books The New Turing Omnibus. The Turing Omnibus is a great computer science book for beginners. It covers, in detail, essential topics in computer science including: finite automata, turning machines, NP-completeness. Each topic is well covered yet it is readable and comprehensible even for the non computer science student. I wouldn't recommend this book for your grandmother (unless she is into that stuff) but if you have an interest in computer science but are not trained in the field this is the book to get.

In addition to these great books (and others he has written) Dewdney was the author of many Computer Recreations articles (later mathematical recreations) in Scientific American from 1984 - 1991 in one article of which he invented Core Wars. Dewdney is currently a Professor Emeritus of the University of Western Ontario.