An elaborate grassroots marketing campaign is softening the ground for Joss Whedon's Serenity, due for wide release on September 30th.  The campaign is centered around a Website for the 'Browncoats,' a fan group named after a faction from the movie.  Fans accumulate credits by involvement in fan activities, from posting on the blog to recruiting new members, and can then redeem them for Serenity merchandise through the site.  Dozens of late-night underground screenings of the preliminary cut of the movie have also been organized through the site.