Online stuff:

I have several friends in the DC area who I met because I made this post.

I found my job because I applied to a CFAR workshop, and that led me to attend the Effective Altruism Summit instead (funny story there), which is where I first met the team I work with.

Phil and Eliezer have critiqued my fiction, and I've done the same for Phil and Vaniver.

Meatspace stuff:

I met about a dozen good friends in Boston through LW meetups and lived with several of them before I moved to SF.

These days, my primary social group is maybe 50% self-identified rationalists and 100% people who are serious about existential risk and laugh at jokes about fundamental epistemology.