The couple takes their dogs for a walk in a Los Angeles park. Plus: Miley & Justin, Beyoncé, Robert Pattinson and more

FANTASTIC FOUR

After sharing the stage for a duet of her song, "No Air," American Idol alum Jordin Sparks rejoins the Jonas Brothers – (from left) Kevin, Joe and Nick – to celebrate the launch of their new book, Burning Up: On Tour with the Jonas Brothers, Monday at West Hollywood's Sunset Tower Hotel.