This is SO obvious it makes me wanna cry. Go to the scene when "Gene" rejects the broken projector and uses the blackboard. Look at the microphone dangling RIGHT NEXT TO HIS HEAD. At first I thought this was the string to pull down the sheet thingy, but wait! It goes to a different camera angle, this time the screen is panned out, and no more microphone. Then it goes back to the original angle, and there it is..dangling down about a foot from the top of the screen. What a good movie, though!