Aaargh! Just have to vent - tonight in my class, about 1/3 of the way through, a woman waltzed in to the very front row, got on a bike, and proceeded to do whatever she felt like (not following any of my cues) for about 10 minutes or so. Then, she just got off the bike and left! There - I feel better. What do you do when this happens in your classes?
(Thanks ;-)