The V sign with the outside of your hand facing the person stems from English archers taunting the French on the battlefield, as those two fingers were the ones they would use to knock and fire the arrow. When the archers were captured, the French would cut of those two fingers :D

I'd heard a similar story about the French with the origin of the one finger salute. Which explained why the "bird" was offensive to the French and not to the British.

That was really interesting. I have been using the "Corna" for a while not knowing that it had ties to Satanists...

What about El "Shocker"?

Actually, I believe what Jenna Bush was saying was not "rock on", but Hook'em Horns, which is a hand signal University of Texas fans use.

She lived in Austin for some time, while her dad was governor, and after he left for Washington.

The Shocker doesn't have different meanings in different cultures, which was the criteria of the list.

Although number one doesn't fit that either.