This animation was done by a Javan Ivy, a student at Pratt University. The technique, which he refers to as "stratastencil" is done by stacking pages of cut stencils.
I'm not as much of a computer geek as the big Carrot himself, but as his friend and fellow contributor, I'm happy to call myself a technophile (or is that the same thing?). In any case, a few of you might appreciate these software structures based on Sol Lewitt drawings. They're created by Casey Reas. The Whitney Museum has more of this, and as I recall, they put on a great show called "BitStreams" way back when.
You can do live chroma key with not just photos, but video in Leopard's P
Yet another paint program for the mac, Drawit has two things going for it: