Q: "How many Romulans does it take to screw in a light bulb?"
A: "Twelve; one to screw the light-bulb in, and eleven to self-destruct
the ship out of disgrace."
[Warning: do not tell this joke to Romulans or else be ready for
a fight. They consider this it to be a discrace, though it's
pretty good for a LBJ. Ed.]