I have organized a two-day course in supercomputing, which I am teaching along with another colleague. I have done this course in one form or another for five years now. It is primarily aimed at summer interns, so that they can learn the basics of parallel programming and using a supercomputer.
Last year I think we had maybe 30 people signed up for each day. This year, we had to close registration yesterday after exceeding 80 registrants for each day of the course. The capacity of the room is about 70, and I'm counting on some people just not showing up.
I think we will have to offer the course again sometime during the fall or winter, because it was unusually popular this year with staff members and postdocs.