Last minute costumes seem to be most successful when they are conceptual such as "E-Male," where a guy wears a big "E" on his shirt, or "Static Cling," an oldie but goodie costume made by pinning a sock to a shirt.You're sure to get a few groans when fellow partygoers get the punch line, but it's better than throwing a sheet over your head and going as a ghost.And, when in doubt, rifle through your closet for clothes from days gone by and go as a decade such as the 70s or 80s!