You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.

Category: STAND BY YOUR MANNEQUIN 
Clue: In a magazine called The Show Window, this Oz creator dispensed advice on mannequins & creative display
l. frank baum

Category: DUMB GUYS' GREATEST INVENTIONS 
Clue: Dumb guys think it's cool they get to slide their own credit card at the store; even cooler? This word for "slide"
swipe

Category: IN THE PAST MILLENNIUM 
Clue: In 1066 this group conquered England

normans