Clack on. Clack off.
The things you learn overseas ... we had a story in yesterday's paper that described a woman as a "clacker." The reference came from the movie "The Devil Wears Prada," and was about a woman who wore high-heels as she clack-clack-clacked down the hall. Anyway, one of the editors asked what a "clacker" was. We looked it up, and it turns out the word is quite common slang in Australia. It means "anus."