you can get a pretty good idea what the movie is about here:
http://imdb.com/title/tt0401792/board/threads/in a nutshell, the movie is based on three of the many stories by comic artist/writer frank miller about a fictitious city called basin city. it's called sin city by the inhabitants because of the crime, corruption and chaos.
this is from imdb.com:
A collection of interweaving stories all based in the corrupt, crime infested hell-hole that is Basin City. Heavily influenced by film-noir, the main storylines concern a hulking brute called Marv (Mickey Rourke), who is seeking the murderer of a beautiful woman who was killed while asleep in bed with him; an ex-photographer called Dwight (Clive Owen) who accidentally kills a hero cop and has to cover it up; and a soon-to-be-retiring policeman called Hartigan (Bruce Willis) who is incarcerated for a crime he didn't commit. All based on the brilliant graphic novels "Sin City", "The Big Fat Kill" and "That Yellow *******", written and illustrated by Frank Miller.
[This message has been edited by TexAgs staff (edited 3/23/2005 7:32a).]