What I've read of the Situationist International has been interesting, but, for any of you who may have read any Situationist works, is it worth it? Are the ideas presented useful, or at least interesting? I know that Situationism was born out of Marxism, so would its ideas be sound if one does not believe Marx's historical theories are correct? If they are worth reading, what is a good book to start with? Include some of the more dense and in-depth stuff as well as lighter, introductory books.