Costume Party?

I just looked at the calendar and realized I have exactly two days to put together a Halloween costume for pre-Halloween weekend. I know this probably doesn't sound like a big deal, but I usually plan my costume months in advance! However, with the past month being one of the busiest in recent history, I barely have time to decide what I'm going to wear to work, let alone to a costume party!

Last year I was Amy Winehouse, and the year before I was Borat. I'm totally at a loss this year, though. I refuse to purchase anything at a Halloween store, and I'm not reusing a costume from years' past.

HELP!