Start with a rousing documentary, like Robert Greenwald's Wal-Mart: The High Cost of Low Price.
Invite a bunch of people over for a viewing. Serve snacks. Moveon.org has instructions and advice.
After the movie, give people time for discussion and an outlet for action: Printed postcards to political leaders, or info on petitions or upcoming rallies.
Watch what happens.
Photos from Against The Wall and Brand New Films
YES! Magazine Graphic 2007