I've recently started a tumblr dedicated to teaching people what amounts to Rationality 101. This post isn't about advertising that blog, since the sort of people that actually read Less Wrong are unlikely to be the target audience. Rather, I'd like to ask the community for input on what are the most important concepts I could put on that blog.

(For those that would like to follow this endeavor, but don't like tumblr, I've got a parallel blog on wordpress)