Though we’re flooded with group deals of every size shape and flavor every day, sometimes one stands out from the pack. Or in this case: swings, twirls and gyrates out from the pack. Drop $20 today and you could drop yourself into an introductory pole dancing class in the city via Living Social and S Factor. It’s posited as a 50-percent-off fitness buy — “Enjoy becoming a long, lean, and self-assured babe while stripping off pounds and inhibitions” — but of course, you could recoup the money right away, seeing as the last time we were around pole dancers we also dropped $20….