Check out this fun mechanical bank (or kinetic sculpture depending on your point of view) by Gina Kamentsky. I suppose it could also be used as an automatic coin-flipper, but it may throw the coins a bit too consistently for that. Like many of her "Mechanical Confections", this one uses a small wind-up motor to power the action. This is an older piece made back in 2003 as part of a series of mechanical penny banks she created.
Here is where you can see more kinetic art by Gina Kamentsky.
[ Thanks Christoph! ]