Dynamic face substitution
Kyle McDonald and Arturo Castro play around with a face tracker and color interpolation to replace their own faces, in real-time, with celebrities such as that of Brad Pitt and Paris Hilton. Awesome. And creepy.
See Castro's video of him doing the same thing, but with a different blending algorithm. His looks more like a maleable mask rather than a face substitution.
Grab the code on GitHub.