Isn't that the thing from Inglorious Bastards?

I've started doing it all the time now as well, as it's valid ASL and we have two hard of hearing children, one of which communicates primarily with sign.

Most of Europe (outside of the UK) does this.

I use my index finger and my pinky with my middle finger curling around my ring finger. As a white foreigner, I show them horizontally on the east coast of the US like an E and vertically on the west coast like a W to try to fit in better. ;)