Perhaps you didn´t follow my advice and start early? Are you scrounging around at the last minute for a costume idea?
This list is clever, lots of PUNS. Some good ones:
Dress in pink and carry a feather. What are you? Tickled pink.
Affix one couch cushion to the front of you and one to the back. What are you? The lost TV remote.
An empty box of cereal. A toy knife. Instant “Cereal Killer.”
Once you tell the joke however, what do you do?
This is from and has 9 pages of easy costume ideas, nothing surprising, but it may spark something for you.
SCA has a no-sew costume page for historic garb.
Togas are quick and cheap and can be accessorized in interesting ways. Check this list of gods and goddesses to figure out a divine name for yourself.
Shoes to match whatever you come up with, made of your favorite art material – duct tape.
My favorite quickie costume of 2010 is  the Umbrella Bat from Evil Mad Scientists
And of course, if you are in the Asheville area,  you can come down to the studio and see what we’ve got.