There's a rule in my house that says the kids have until the count of five to do what they're supposed to be doing - whether that's turning the TV off and getting upstairs, eating their breakfasts or to stop throttling each other. It's a system that works pretty well and generally speaking, by the time I shout "Five!" said kid has ceased evilness and is good again.
However, because the youngest is a copycat of extraordinary measure, I heard her berating her brother with this yesterday:
"You got 'til five... One... Four.... Sixteeen... Twenty two.... FIVE!"
Non-linearity is *the* thing in our house, it seems.