I've been on IRC non-stop since 1997; it's where the majority of my closest friends and I keep in touch. I also run an IRC channel for the class I teach, and it

I've been on IRC non-stop since 1997; it's where the majority of my closest friends and I keep in touch. I also run an IRC channel for the class I teach, and it's the primary communication means for most students. As for YC, there's the ##startups channel on Freenode, unofficially.