Went to Sam's where Kevin posed the following question he heard in grad algo, evidently due to Avrim: suppose you have a circular graph of n nodes, and you start on some fixed node. Flipping a coin at each stage to move left or right, which node is going to be the last one you first encounter? (i.e. find a probability distribution)
Got about half the category theory grading done, and a very little Twelf hacking.
Later went over to the UC and found a game of Ricochet Robot.