How do you do this?

I just saw this website on the last post. Does anyone know how to make that effect? It is probably 2 layers and some scripted masking, right? But how do you do that?

http://www.dapper.com/

actually, that’s tweened masking… my guess…

yes…they use two layers, the front layer is obviously a movie clip wif tweened masking, the bottom layer’s juz a plain image background…