PlayChess offers online chess tournaments and casual games for players from beginners to masters. The games are played on online chess boards with a time schedule in the order of one move per day. The site offers include annotating your games, thematic tournaments, rating calculation, PGN downloads and much more.
PlayChess is a correspondence chess servers with about 2000 visitors each day. (Text sent by Thomas Stahl, webmaster of Playchess.)
Playchess: http://www.playchess.de/service.cgi