true story... a guy at work was moving and he brought an old cuckcoo clock to the shop. One of the bellows that made the clock Cuckcoo was worn out, so I took the clock and rigged the internals with a bolt that would fall and hit the button of one of those swearing keychain fobs, instead of dropping the set of bellows... the result was every 15 minutes, the clock would chime, "F*** YOU!".
We called it the "F.U. Cuckcoo". 20 years later I run into guys that are still amazed that I was able to make it work.