The Arduino makes a fierce return, this time in the form of a hat. Using flex sensors and a hat-mounted Arduino, Instructables user RonanOD created a game of Pong where you use your eyebrows for play. The hat senses how much pressure is being created along the brim and uses the related data as input in the game. Instructions are available, but I can’t promise it’ll be fun twitching your eyebrows like Mr. Bean all day long.