It's a nightmare scenario: You've got a party to attend on in the Hamptons Saturday night, but accidentally left your dress behind in the city. The thought of trudging all the way back to Manhattan has you on the verge of tears, and the Target in Riverhead just isn't gonna cut it. Well, dry your eyes, young clothes horse: Starting July 11th, you can log on to Net-a-Porter and get same-day delivery service, courtesy of StndAir. If you place your order by 10 a.m. you'll have it just in time for dinner!