It would be fun to make a passphrase generator that always includes a profanity.

Now I'm trying to remember where I read the story about somebody who was in a programming class and was writing some program that took user input, and figured that it should be smart enough not to repeat curse words. So they started writing down all the curse words it should know not to say, and that was about the extent of what they had done when the teacher came around to see how everything was going.