One of my first Processing projects was a single pixel display. (By the way, I don’t think the link will work because you need to be running it locally or something, but I’m keeping it since it provides a nice way to package the sketch.) The sketch does nothing but display a square whose color corresponds to the average seen by my laptop’s webcam.
Why? A few reasons. I wanted to hook it up to my Arduino and an RGB LED and use it as an Ambilight clone, or perhaps a TV simulator (makes a room look like a TV is on from the outside). I also have a few more “artistic” ideas. For example, I thought it would be funny to explore the lower limits of video resolution, especially as it relates to the impact of the content therein (think about obscenity and watching analog scrambled porn channels as a kid… or was I the only one).
It’s interesting to note that it does clearly respond to things (like placing my hand in front of the camera makes it turn reddish). But it also tends towards 50% gray as the automatic white balance kicks in. Any steady scene becomes steady gray after a few seconds.
Perhaps I’ll post a video or screencast or something.