Allegra Coleman is a hoax (fictional and imaginary) — made up by writer
Martha Sherrill[?] in 1996 in
Esquire Magazine and "played" by model
Ali Larter.
Article in Salon (
http://www.salon.com/media/media961101.html)
A Esquire frontpage (http://www.celebritywonder.com/free/colema~1_allegr~2.jpg.html)