We've all (well...) seen one. The four-inch diameter black ball with the eight on it that looks a giant version of a pool ball. You ask it a question and then turn it over. Up from the indigo pool of infinite mystery arises the ghostly answer inscribed inside a triangle in some alien font. "Reply hazy. Try again."

From what strange abysm of inventorhood comes this taunting apparation? Who makes them? Who sells them? Why? We should not ask. It is a mystery.