The Chicago Tribune has a post highlighting the current trend in Halloween costumes:

• If Halloween retailers could encapsulate 2007 into one word, it'd be sexy.
  
  Short skirts are getting shorter; necklines are plunging faster than the real estate market; wholesome characters are becoming just a wee bit less wholesome.
  
  "Young girls [are] going for sexy, older moms are going for French maid and nurses," said Andy Anderson, president of the National Costumers Association.
  
  So what happens when we combine one of our most endearing Halloween costume themes, "The Wizard of Oz," with this trend toward sexiness? Plenty of options, it turns out--as cheap or expensive, and as prudish or sexy as you want.

TOP SEXY HALLOWEEN COSTUMES