Social media for mathematicians: Math Overflow

I wouldn't be surprised if ( research ) mathematicians were so ( Asperger / social anxious / Nerd / whatever buzzword you like ) that they stay away from Facebook. - The quality of Facebook is that you meet people that you wouldn't have met otherwise, because they are completely out of all the circles you are in. - Anyway, a place where research Mathematicians ask questions ( in a way programmers do for example ) is the site Math Overflow, it is set up like Stack Overflow, a well known site for programmers. Registration is open to anyone. Only questions on the graduate and research level though. No place to search for help with TMAs but a fascinating place to get a feel for what it is like on the frontline of our science.

Math Overflow ( Research )

Math Stack Exchange ( B.Sc. students )