I always wanted to do something like this with an Arduino but never got around to it. When I saw the Hue I was pretty excited, until I saw the price tag. $200 for 3 bulbs? I'll pass for now. I'm assuming it's only a matter of time before they become reasonably priced.

For $199 you get 3 bulbs and the wireless "hub". Additional bulbs to expand your collection are $59.