UNIX convention
Joan, on an airplane, strikes up a conversation with the geeky computer programmer sitting next to her.
"Where are you going?" asks Joan.
"I'm going to San Jose," says the geek, "to a UNIX convention."
Later, Joan's husband picks her up at the airport. "How was the flight?" he asks.
"Oh, fine," says Joan. "I sat next to this guy I felt really sorry for."
"Why'd you feel sorry for him?"
"He didn't have any testicles."
"What?!" says the husband. "And just how did you learn *that*?"
"Because," says Joan, "he said he was going to a eunuchs' convention."