Spending five minutes thinking about it:

Boredom. What it is, how to notice it, what to do about it. Eliezer wrote some about this in Fun Theory but it could probably be expanded on. (and the topic is amusing to me for...Reasons)

To recurse on the subject: Idea generation. How new ideas work, how to come up with them on demand, how to separate good ones from bad ones.

Dealing with irrationality in others. e.g. if you're part of a group that's mindkilling itself, and you can't just walk away, how can you de-mindkill the group? Successfully, that is. Yvain wrote a bit about this here with regard to individuals, but there's probably room for more.

...I had three more suggestions that I thought of while away from the keyboard for a few minutes, but they all went out of my head before I made it back, even though I specifically tried to note them. If someone knows why this sort of thing happens, it would be nice to write it up, because it happens to me all the time and it drives me insane.

(yes, I know the fix is to carry a notebook everywhere and use it religiously. I still want to know why it happens)