Alan Lee and John Howe do concept art for the new Hobbit movie in 3D. John does the red, Alan does the blue, and Peter Jackson looks at the result through anaglyph specs. It's totally wicked. Even though I am not quite sure whether they did this kind of parallel stereo drawing to show off in the documentary, and actually worked separately... it is still totally wicked.
Seen in this piece of video blog:
(There is a sample of combined anaglyph drawing at about 9:45 into the video, and the preceding sequence shows the artists working.)
(P.S. The longer I am thinking of it, the more I am inclined to think it was a joke, and I've been had. Kudos to the Hobbit team, remind me to buy them a beer if our paths ever cross.)