Want to wear something skimpy yet chic? Try a pair of social panties. They are usually brightly colored, ruffled, or sequined. If you can imagine a burlesque dancer wearing them before they strip down to the even racier thong or g-string underneath, then you have social panties.
See also: shirt-cocking.
As with so many other genderqueer aspects of Burner culture, the wearing of social panties is not limited to women. A lover and I spent a good deal of time admiring a skinny boy in a pair of rainbow ruffled panties at a recent Burner house party.
I first heard this word from my friend Kristen at Burning Flipside circa 2006.
Other entries in A Burner Lexicon can be found at http://kitoconnell.com/lexicon/