Loved the idea of a sphere that works like this one...

...by moving in different directions based on co-ordinates entered into a computer. BUT...! The sphere or whatever it was called caused insane amounts of damage just by passing unopposed through many objects, even buildings and so forth. If it passed through PEOPLE and caused a few deaths, then that would change things a lot! As far as I can tell, the only near-casualty was Wolfgang's cat. Oops!