I gave a lecture for a MIT class earlier today, ESD.40: Product Design and Development. The lecture largely discussed how human interaction factors into product design (surprisingly), although a lot of it was mainly intended to introduce students to different aspects of human interaction and motivate them to consider interaction when working on their products. I was a bit concerned half way through the lecture because I was only a 1/3rd of the way through the slides. However, that ended up just being that the first-half of the lecture was slower going than the second half, and things ended perfectly on time.
I did find an amusing video to wake the students up half way through class, courtesy of quirkology.com