Are there any areas of study that you feel are underrepresented here, and would be interesting and useful to lesswrongers?
I feel some topics are getting old (Omega, drama about moderation policy, a newcomer telling us our lack of admiration for his ideas is proof of groupthink, Friendly AI, Cryonics, Epistemic vs. Instrumental Rationality, lamenting how we're a bunch of self-centered nerds, etc. ...), and with a bit of luck, we might have some lurkers that are knowledgeable about interesting areas, and didn't think they could contribute.
Please stick to one topic per comment, so that highly-upvoted topics stand out more clearly.
There are plenty of tutorials for R - just google. I'm sure someone else has written a much better tutorial than I could write.
R is a full blown programming language without a simple to use GUI (at least not in the base package), so if you don't have any programming experience it might be slow going. But the freedom of a programming language makes the learning curve worth it (if you've used SAS, you understand what I mean)
My grad program offers 1 credit course in R to first year grad students, and much of it is available online. When it comes to statistical graphics, the stuff on ggplot2 is particularly relevant, and in the first 2-3 sets of lecture notes.
See also the ggplot2 reference manual