Facebook

Rationalist Facebook things.

Groups

• Brain Debugging Discussion - formally 'Less Wrong', no longer official affiliated
• Effective Altruism - Largest group on effective altruism

People

• https://www.facebook.com/yudkowsky - Eliezer Yudkowsky
• https://www.facebook.com/Xuenay - Kaj Sotala

... add people here! (so long as their profiles are public)

Meetups

Many of the Less Wrong meetup groups have associated Facebook groups.