Recently I've been trying to watch a variety of British television shows, so that I will recognize some of the programming when I'm abroad. I began watching the British comedy-drama Shameless, which has also been remade in the US and airs on Showtime. The show focuses on the Gallagher family, where the patriarch Frank is perpetually drunk and unemployed. His oldest daughter Fiona then must shoulder the responsibility of raising her five younger siblings: Lip, Ian, Carl, Debbie, and Liam.
Throughout the show, I saw some of the characters give the "peace sign" gesture to another character, but could infer it was not meant in a friendly greeting sort of way. Upon further research (ok, I looked it up on Wikipedia), I learned that in the UK and Australia giving the V sign with the palm facing towards you is an insult, almost equivalent to that of giving someone the finger. The gesture is also known as ""The Longbowman Salute," "the two," or "The Tongs." To read more about the origins of the gesture as an insult, visit Wikipedia: V sign. So moral of the story is I must be careful in the non-verbal greetings I give to the locals while in London!