That's funny that you posted that... Me and a friend did something similar (not during an exam but was still funny as hell). We listened to the lecture and such, and about every 5 minutes or so, we'd change seats. We were on opposite sides of the room. We'd pass eachother and say things like "How are you today" "Crazy weather isn't it?" "How 'bout them yankees" and such. We were sent outside the classroom in the end. I stood at the door, then walked in a short while after and asked the teacher to talk louder because I couldn't hear him. Detention wasn't that bad.... I laughed through most of it.