Twirling my curly hair, speaking to myself with an English, Russian, or Spanish accent, speaking to my FRIENDS in an English, Russian, or Spanish accent, using Wikipedia to do ALL of my history projects, snapping my fingers rhythmically, humming songs that don't exist, pretending to fight the air...
And my favorite: Looking around the room to see what I would do if a massive zombie-attack happened. Currently, because I'm at school, I'd prop up the desks that these computers are on against the doors, turn off the lights, and duck down, probably using the towers as weapons.