Rats. Math.SE is addictive. My therapist suggested that I try limiting this hobby to three days per week, and re-evaluate the situation the next time we meet. So I will only be seen on Mondays, Wednesdays and Saturdays. At least for a little while.
Mostly I teach here. I want to encourage beginning students to think for themselves, so I use a lot of hints and comments. More advanced questions I often just answer.
However, I don't do 1-on-1 chat. Don't ask. My answers and comments are for all to see, so I don't like to hide them. Also I feel that entering a chatroom carries with it an obligation to continue an on-line discussion, and then I would not be using my time on my own terms.
Relevant personal history:
PhD from Notre Dame in '90.
Drifted from representation theory of algebraic groups to applications of algebra into telecommunications, mostly coding theory, and lately mostly teaching at college level.
3 graduate students with awarded PhDs
I have mostly worked at our local University at Turku, Finland. At one point I tried working for Nokia Research Center. It was ok, but an old dog didn't learn all the tricks, and then they downsized, so I returned to the Uni as a tenured lecturer.
Q&A for people studying math at any level and professionals in related fields
Q&A for users of Mathematica
Q&A for linguists, etymologists, and serious English language enthusiasts
Q&A for theoretical computer scientists and researchers in related fields
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Q&A for active researchers, academics and students of physics
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Q&A for software developers, mathematicians and others interested in cryptography