Saul Steinberg was a cartoonist for The New Yorker, and Inge Morath was a photographer. When Morath asked to take a portrait of Steinberg, he showed up with a paper bag mask on his face. At least, that’s what Wikipedia says, and we all know Wikipedia doesn’t lie.
More Morath: http://www.magnumphotos.com/Archive/C.aspx?VP=Mod_ViewBoxInsertion.ViewBoxInsertion_VPage&R=2K7O3R13MCZT&RP=Mod_ViewBox.ViewBoxThumb_VPage&CT=Album&SP=Album
More Steinberg: http://www.adambaumgoldgallery.com/steinberg/1DrawingsPage1.html