Apperceptive recently added a new member to the team and she's already giving me great info. She's currently riding the PATH train to work and mentioned that they have these crazy flipbook style ads in the subways. As you pass by in the dark tunnel, there are a series of images pasted to the wall. Like a flip-book, the images in succession look like a movie. This video should give you a better idea of what I mean.

I have yet to see this in person but I'm completely awed by the concept. I might (gasp!) take a trip on the PATH just to check it out.

Update: I just found out that this was invented by Josh Spodek and the company he founded is Submedia. The sites have tons of info and some more videos. It turns out I have two friends who know Josh. Small world!