They called the crap that I played with as a kid "Magic Markers," but this is the real deal. Musicians have been sampling music and sounds from other artists for years. Now artists have the technology to sample textures, colors, basically all of life and art and then literally brush it onto a digital canvas. And for the first time you can paint with video.
I first saw the I/O brush in action on Rocketboom, a (hit or miss) daily video log, and thought the whole thing was faked. But those wacky, lovable nerds at MIT actually invented this thing. You can learn more about the I/O Brush and watch the magic brush in action at their website.
I don't know if or when the I/O Brush will be available to the public, but don’t be surprised when billboards using video painting start catching your eye.