Okay, let's imagine you have some friends that you don't really like that much. Let's imagine they have a small child. Let's imagine you have to go to their house and it seems appropriate for you to take a gift to that small child.
You want to give the kid something that will really annoy the parents to the point where they'll rip handfuls of hair from their skulls and run screaming into the street. What do you do?
You give the child one of these. To get the full effect, click the button that says "See it in action."