We found Mary-Kate Olsen leaving the 2010 Fashion’s Night Out kick off press conference at City Hall in Manhattan late yesterday afternoon. Mary-Kate and twin sis Ashley have put nearly all of their professional energy into their various fashion lines, which has proven to be a great business move.

The twins have been universally well-received by the fashion world. Mayor Bloomberg, Marc Jacobs, Donna Karan, and Anna Wintour joined in to promote the event, where 1000 stores will stay open until 11 p.m. on September 10th for special shows and events to promote New York City’s critical fashion industry.

Mary-Kate and Ashley’s high-end line Elizabeth and James will have its first pop up shop for a week in the West Village to advertise their clothes, with other designers coming up with similarly creative promotions throughout the city.