Olivia Palermo: "Hangover Part II" Screening

Olivia Palermo and Johannes Huebl attend the Cinema Society & Bing screening of "The Hangover Part II" at The Top of The Standard on May 23, 2011 in New York City. Credit: Wire Image

Holly Madison: "The Hangover Part II" Premiere

Holly Madison arrives at the Las Vegas premiere of the Warner Bros. Pictures movie, "The Hangover Part II" at the Planet Hollywood Resort & Casino May 21, 2011 in Las Vegas, Nevada. Credit: ZimbioPhotos by Ethan Miller/Getty Images North America

Angel Porrino: "The Hangover Part II" Premiere

Angel Porrino arrives at the Las Vegas premiere of the Warner Bros. Pictures movie, "The Hangover Part II" at the Planet Hollywood Resort & Casino May 21, 2011 in Las Vegas, Nevada.Credit: ZimbioPhotos by Ethan Miller/Getty Images North America

Jamie Chung: "The Hangover Part II" Premiere

Jamie Chung posed next to a new "The Hangover" slot machine by International Game Technology as they arrive at the Las Vegas premiere of the Warner Bros. Also pictured, Mason Lee and actor Justin Bartha.Credit: ZimbioPhotos by Ethan Miller/Getty Images North America

Jamie Chung: "The Hangover Part II" Premiere

Jamie Chung attended the Los Angeles premiere of "The Hangover Part II" held at the Grauman's Chinese Theater, Los Angeles on May 19, 2011.Credit: ZimbioPhotos by PacificCoastNews.com