Look at this little kid using finger paint to create a pointillist painting of a Mutant Ninja Turtle. Link
As much as I wanted to believe it was real, I'm pretty sure that video is faked. It's just a doll's arm or something. The only time you see the kid's fingers move is the shots where he's filling in solid areas or "blending." I'm sure they sped it up so it wouldn't look as fake. Plus the site at the end of the video (turtlekid.com) is to promote the new movie.