Have a look at the Gunchuck, it comprises of a Nunchuck, an Arduino and a BB-Gun. This would be lots of fun if the gun was changed out with a super soaker and mounted on the peak of your roof. You could use a Web cam to watch the dot at night and terrorize the kids that might be out past their bedtime. I think Quicksilverhacks should use his voice control work to allow him to say fire when the gun should shoot.