I haven't had the time. I'd like to sit in on Mark Schneider's workshop physics, because it seems to be a model of the workshop style. I'd like to sit in on the upper-level probstats course because I don't know enough statistics. I'd like to sit in on the introductory education course. The new History 195 sounds like a very interesting course.
Many tutorials also sound like they'd be a lot of fun.
Maybe it's time to become an undergraduate again. I'm also becoming more and more convinced that the Web will bring little advantage for students who learn in Grinnell-like classrooms. However, I do think that the Web can give us insight into how our students interact with materials. I value my colleagues in mathematics and computer science. The two other computer scientists, John Stone and Henry Walker, are great to work with.