[EricH]

Besides the obvious (mentor matches, whether or not they count towards standings)...

--Obstacle course. Run a randomly-selected/nominated robot through an obstacle course. (Or your own robot.) Get creative with this one.
--Truck pull. Some brave soul volunteers a nice heavy truck or car and acts as brake-person. Fastest to the end of the course (carpeted or not) wins.
--Human-player game. Take FRC game object, run through some semblance of the game with a human or set of humans. Watch out for the Truss!