DasRegelnWirSchon (We'll Settle This Yet) is a German game that closely resembles Nomic. Players take turns playing "Rule cards", which contain new rules, and voting on them. The complete set of rules, translated into English can be found at: 
http://www.gamecabinet.com/rules/DasRegeln.html
A review of the game can be found at: http://www.gamereport.com/tgr11/dasregelnwirschon.html
Descartes games (http://www.jeux-descartes.fr/english.htm) publishes an English language version of this game, called Democrazy.