The MIT IAP Mystery Hunt Puzzle Page

American Crossword Puzzle Tournament — annual crossword tournament and de facto puzzle convention in Stamford, CT
National Puzzlers' League — puzzle society whose members include many Mystery Hunters as well as professional puzzle constructors, holds an annual convention in July

The Internet Anagram Server — anagram solver/generator
Purdue dictionaries and wordlists — lots of lists in lots of languages (via ftp)
National Puzzlers' League members area — search or download word lists (paid membership required)

Atlantic Monthly — monthly cryptic crossword
mathpuzzle.com — Math, logic and other puzzles, updated weekly
New York Times — daily crossword (subscription required)
Puzzability — company providing puzzles on their web site, and custom-order puzzles
Syndicate — Vocabulary Word Puzzles (and a biweekly crossword)
Conceptis puzzle — PBNs and similar puzzles (free weekly puzzles with registration)
Games Magazine's site — Crosswords, PbNs, and some other content from the print magazine.
Triple Play Puzzles — Crosswords, variety word puzzles, cryptics

Note: this directory is currently being edited. Send suggestions to us.