Guess it's only fair that I go first, then...
Phrase: "Tricycle granny"
This phrase is used in my house to refer to the phenomenon that occurs when you are anxiously awaiting a package or piece of mail, and every two seconds you think you hear the truck or the guy that's supposed to bring it. The phrase originated when I remarked (on one such occasion) that every two seconds I thought I heard a truck loud enough to be a semi, and then I look out and there'd be something ridiculous instead like some little old granny on a tricycle riding down the street ringing her little bell. The remark caught on.
Now it's common to hear in our house, when someone is expecting a package, and looks out the window to see if it's there, for someone else to ask, "is it your package, or just a tricycle granny?"