So far this season, the Yves Saint Laurent Besace bag has already been spotted on the arms of Demi Moore, Gisele Bundchen, Jennifer Aniston, Jessica Alba, Julianne Moore, Kylie Minogue, Lily Allen, Sarah Jessica Parker, and Sienna Miller.Whew! What a celeb list.Is this the new It-bag? Is the “Muse” bag history? We’re keen on the Besace’s clean utilitarian lines and cozy aesthetic. It’s totes totable.