"Seriously.js is a real-time, node-based video compositor for the web" (from the readme on the GitHub repo), and might be of general interest to those into Machine Vision, Imaging, and especially OK GO. How to work this demo: 1) play the video, 2) toggle processing styles with buttons on the bottom of the video, 3) be amazed: http://seriouslyjs.org/
(Lyrics are colorful, perhaps not appropriate for blaring aloud at work or with your impressionable little ones -- turn the volume low, and the video is quite fun for the kids!)
Raw video still, filmed in front of a green screen:
British Invasion filter, applied real-time with Javascript in your browser:
(Sorry IE; this demo works in Chrome/Firefox)