I finally finished my doorbell color changer, a modification to a hardware store lighted doorbell using a single RGB LED and an AVR microcontroller. I'll have to write an article about this project later. For now, take a look at the pictures. The night shots really don't do it justice; maybe I'll take some better video as soon as I can track down a tripod.
The shifting hues promise further weirdness inside—ring the bell if you dare!