Most people have seen the toy Magic Eight Ball*. If not see link, but suffice it to say it gives you random answers to yes/no questions via a free-floating buoyant icosahedron (20 sided polygon) in a dark liquid. I propose to build a modified version.
Put a radio-controlled three-position
solenoid with a weight on the shaft inside the icosahedron on which the answers are printed. Arrange the answers so that a full positive answer is on the side where one end of the solenoid points, and a full negative is on the other. (Several of the standard answers are prevarications).
Now you can, using a discreetly hidden remote, command the solenoid into three positions. In the default position, the weight should be dead center of the answer icosahedron, so everything works normally. You get a random answer.
Throw the solenoid to one side or the other, and the icosahedron will be off balance, and the answer on the opposite side will always float to the top. You can now command a yes or no answer on your eight ball. Think of the fun you can have showing your friends your magic eight ball that is always right (or always wrong).
The one engineering problem is providing power to the radio & solenoid inside. I think this could be done through an induction charger plate inside the ball at the opposite end from the answer window. The ball is set in its base station upside down, and the answer ball will float up against it and charge a small battery inside.
*"Magic 8-Ball" is a trademark of Mattel.