This is a project Squintus and I have been discussing. A video would pretty much explain it all:
We plan on rigging it to his doorbell so that it fires a set number of Smarties (2-3), or possibly just have it controlled by us inside. Also, we plan on having a webcam on/near it to watch the fun.
--John (and please call me John, it's really weird to be called by my username)
Fight MS Paint abominations! If you don't have a camera, go here, and pick something 3 megapixels or higher.