One of my favorite Richard K. Feynmann anecdotes arises from the Space Shuttle program. In one of the two books on him, a friend is reminiscing about the time that Feynmann sent him a diagram of NASA's proposed zero-gravity toilet. Immediately behind the user's...er, behind, there is a spinning device which NASA has labeled 'Solid/Fluid Waste Separator.' Next to it, Feynmann had pencilled in an arrow pointing to the device, with the notation "As near as I can figure, the shit is supposed to hit the fan!"

The man was a genius.