I have already seen a prototype of similar technology on a television show from Canada called "Dragon's Den" although I think it was a different company. I have no doubt there are others coming up with this "poster clip" ability. The advertising opportunities are endless. You can bet your bottom dollar that James Cameron will be using similar tech for his "Avatar" posters - like this spy one that has already been leaked:
We knew it was coming and now its here. A Canadian company by the name of RabbitHoles Media has come up with a way to display six to eight seconds of 2D OR 3D movie clips and print them on to a poster that "moves" as the viewer walks past them.
SAME DAY UPDATE: James Cameron DID IN FACT inquire into this company's technology back when they were known as XYZ RGB. So we will most likely be seeing Avatar 3D posters with this technology sometime in 2009! Steve Jobs has also expressed interest in this company and their products. (Source canada.com)
Here is the image that they will be showing off at Comic Con soon - remember that this moving "poster clip" is on a flat piece of media!