Rational Wiki. Quite a lot of useful and generally cool stuff here, although it's all preaching to the choir.
Our purpose here at RationalWiki includes:
Analyzing and refuting pseudoscience and the anti-science movement.
Documenting the full range of crank ideas.
Explorations of authoritarianism and fundamentalism.
Analysis and criticism of how these subjects are handled in the media.
Good for refuting whatever nonsense your Uncle Max comes up with, as well as amusing and enlightening yourself.