Here's a 32-minute presentation I made to provide an introduction to some of the core LessWrong concepts for a general audience:

You Are A Brain [YouTube]

You Are a Brain [Google Slides] - public domain

I already posted this here in 2009 and some commenters asked for a video, so I immediately recorded one six years later. This time the audience isn't teens from my former youth group, it's employees who work at my software company where we have a seminar series on Thursday afternoons.