Gawker is starting a "Hall of Shame" for magazines and newspapers that don't pay their writers (or take a long time to pay up). So far they've mentioned New York Observer and The Player. See here for the posts: http://www.gawker.com/news/hall-of-shame/
They're looking for tips. I've already sent them links to threads here about True Confessions, True Love, Hooters Magazine, Northern Cards, and Girl's Life. If you have others, send 'em over to Gawker (and please post about them here, too, to let other writers know about your experiences).