Last year we made a list of last-minute, book-inspired Halloween costumes. Those are definitely still good options, but I ran across an even easier costume this year: dressing up as Sookie Stackhouse from the Charlaine Harris books and True Blood TV series. Now, ideally you'd go all-out and get a blond wig, but if you're low on cash you can just skip that and go as one of the other waitresses at Sookie's job (the ones with the high mortality rate). You'll need a pair of tiny shorts, sneakers, a tight white t-shirt, and a tray. Write "Merlotte's" on the shirt and you're golden! Best of all, at this time of year you'll probably be able to find tiny shorts and white t-shirts galore in the deepest recesses of the clearance aisle.
I wouldn't trick-or-treat in this, though. You'd freeze vital bits off.