25 best movie cameos ever

Annie Hall – Marshall McLuhan (1977)

Ever been stuck in a queue next to someone who won't stop pontificating on a subject they know nothing about? Woody Allen feels your pain. So in this scene, Allen wheels out noted academic Marshall McLuhan to decisively shut down a bumptious university professor. "You know nothing of my work. How you got to teach a course in anything is amazing," says McLuhan, delivering the greatest academic smackdown in film history.