The lovely ladies who dressed up for last night's Costume Institute Gala kept the good times rolling at the afterparty held at the Standard Hotel. Diane Kruger ditched the high-slitted Jason Wu gown she wore on the red carpet for a short black number from the designer, though she kept her best accessory, boyfriend Joshua Jackson, close. Gwyneth Paltrow continued the festivities in her backless Stella McCartney, which earned her a place on the best dressed of the Met Ball list. She had her good pals Jay-Z and Beyoncé Knowles, in Pucci, along for the fun, while a Miu Miu-clad Michelle Williams made the rounds with a guy friend. Kristen Stewart was a belle of the ball in a special Proenza Schouler gown, and she had one of the label's designers, Lazaro Hernandez, as her date to the late bash with her real-life love, Robert Pattinson, abroad showing off Water For Elephants in Europe.