jack a photo booth.
More about jack a photo booth.
This might take a little stalking, but it'll be worth it.
Basically just scope out a photo booth at a mall or whatever, and when someone goes to use it - stick your head in mid-shot. It'd be awesome if you were wearing some sort of mask or....whatever, but it HAS to be vid, not just a pic.
Want some added props? Convince your new friend to give you the pic.