The Fantasy Rules Committee is a nomic-like game that started as a special committee of NomicWorld. It did however survive the disbanding of the latter game, and still exists as an independent entity.
In FRC (as it is called in short), there are subsequent rounds. Each round starts with all players being eligible (except one who functions as the judge). Players try to make valid rules, that is, rules consistent with all previous ones. A valid rule extends a player's eligibility to fourteen days after the rule was posted, but an invalid one decreases it by two days. The last eligible player (who in almost all cases is also the player who posted the last valid rule) is the winner, and will function as the judge in the next round.
As of 2007-07-16, the FRC is in Round 254.
Web page:
http://www.win.tue.nl/cs/fm/engels/frc/
Mailing list:
List: http://groups.google.com/group/frc-play
Archives: http://www.sir-toby.com/archives/FRC/
(The Google Groups page contains the most recent archives.)
To play, just subscribe and (attempt to) post a rule during the first two weeks of some round. No specific registration is required.