With her pooch in tow, the Gossip Girl star celebrates her 21st b-day on the New York City set of her show. Plus: Ashlee Simpson, Lindsay Lohan, Paris Hilton and more

  • SOLID GOLD photo | Heidi Montag

Credit: James Breeden/Pacific Coast News

Published: Monday Aug 25, 2008 | 05:50 PM EDT

SOLID GOLD

The Hills' Heidi Montag catches the dance fever while filming a video for her song "Overdosin'" in Los Angeles recently.