Lenticularism!

I read Photojojo regularly, and I found this one pretty intriguing -- Lenticular street art in Berlin.

You have probably seen lenticular printing before, but may not have known what it is called. It's often used on baseball cards, fast-food promotional drink cups, etc., and often depicts multiple images of a subject in motion, such as a baseball player swinging a bat. The image appears to move as your angle of view changes.

This use of lenticularism (is that a word?) is very cool!