I think I first came to this site via a link on another forum to the "Three Worlds Collide" story... or the "That Alien Message" one.
And then I read more articles. I find rationality, cryonics and the singularity to be very interesting, and most of the articles I've seen so far are about those topics.
I'm in the UK, and I'll be in sixth form in september, will do maths, electronics, chemistry and physics.
I don't yet feel I can identify as a rationalist, but I don't think I'll be able to assess this until I catch myself thinking irrationally in response to something, either before or after the fact. I'm not sure how I can even define "me as a rationalist"...