Forums, newsgroups and e-mailing lists
• Grey Labyrinth Discussion Forums
http://www.greylabyrinth.com/cgi-bin/Ultimate.cgi
• The rec.puzzles archive
The rec.puzzles archive is a list of puzzles, categorized by subject area. Each puzzle includes a solution, compiled from various sources, which is supposed to be definitive. Here are the subjects: analysis, analogies, arithmetic ,combinatorics , cryptology, decision, geometry, games, group, induction, language, language equations, logic, physics, pickover, probability, putnam tests, real-life, references, riddles, series, trivia, Paul Sloane"s lateral thinking puzzles, Jed Hartman"s collection of situation puzzles. http://rec-puzzles.org/ unsenet newsgroup: news:rec.puzzles
• Geometry Puzzles
Post here interesting problems and conundrums that require only a knowledge of pre-college geometry, as well as discussions and solutions. This forum can be accessed in several different ways: As a Web-based discussion: http://www.mathforum.com/epigone/geometry-puzzles/ As a mailing list: To subscribe, send email to majordomo@mathforum.org with the phrase "subscribe geometry-puzzles" (no quotes) in the body of the message. As a Usenet newsgroup: View geometry.puzzles within the newsreader of your choice.
• Nobnet
This is a list for specialists in mechanical and logic puzzles. To subscribe, e-mail Junk Kato at owner-nobnet@iijnet.or.jp. http://www02.so-net.ne.jp/~nobnet/index.html
• Macalester College Problems of the Week
Stan Wagon, a professor in the Mathematics and Computer Science Department at Macalester College, poses a mathematics problem to his students every week. The problems are meant to be accessible to first-year college students, so very little background is needed to understand or solve them. http://www.mathforum.com/wagon/ You can subscribe to the weekly newsletter sending a message to majordomo@mathforum.org with just the words "subscribe macpow" in the body.
• Snark (in Spanish)
Snark es una lista de discusión por correo electrónico en español, que está formada por interesados en intercambiar problemas y soluciones de juegos de ingenio. Esto engloba a la matemática recreativa, los problemas de lógica recreativa, juegos de tablero y problemas sobre ellos, rompecabezas geométricos (poliominos, policubos, tangramas, problemas de partir figuras, etc.), cuadrados mágicos, juegos con el lenguaje (palíndromos, anagramas, cs monovocálicos, etc.), paradojas, y todo aquello que sorprenda, maraville y deje perpleja a la inteligencia. La lista también está abierta para promover actividades que tengan que ver con la difusión de los juegos de ingenio. Para instrucciones de cómo suscribirse y más información: http://www.geocities.com/snarkianos