Speaking of snapping and clapping....
My chapter stepped outside the norm and did a 'hand-wave' like you were fanning yourself on a hot day. The wave meant 'I agree' and our poor new members (and even other A-Phis from different chapters) were always so confused by our bizarre hand motions. I know where the wave originated from, but I have no idea how it mutated in such a way. It's very addictive though - I find myself doing it even when I am talking to people who are not from my chapter!