Gwen Stefani, Angelina Jolie, Shiloh, Knox & Vivienne
While Brad is busy working on his flick World War Z in the U.K., Angie and her brood hang with Gwen and Gavin's boys at their London house. Not a bad way to kill time!
Jessica Alba, Rebecca Gayheart, Eric Dane & Billie
Surprise! Jess and Honor (not pictured) have an impromptu playdate with McSteamy & Co. when both families wind up at the same Beverly Hills park in May 2011.
Garcelle Beauvais, Halle Berry, Nahla, Jax & Jaid
The swing set is the hottest spot in Bev Hills for these cutie pies—and no doubt these actresses are the hottest mommies in the park.
Hugh Jackman, Oscar & Dashiell John
In December 2009, Cate Blanchett dropped off her three boys at a Big Apple park for what looks like an awesome snowball fight with the X-Men star (the Aussie actors are good buddies) and his son, Oscar (left). Can we play, too?!
Kourtney Kardashian & Mason
E!'s most adorable star wasn't the only famous tot at Harlow Madden's celebuspawn-studded birthday bash in January 2011. Guests also included Chris Ivery, Ellen Pompeo and Stella Luna; Gwen Stefani, Gavin Rossdale, Kingston and Zuma; Jessica Alba, Cash Warren and Honor; and Tobey Maguire's wife, Jennifer Meyer, brought along their kids Ruby and Otis. She's so popular!
Gwen Stefani & Zuma
Little Zuma's got his party face on as he and mama Gwen head into Harlow's A-list birthday party.
Liev Schreiber, Naomi Watts, Alexander & Samuel
Angelina Jolie's Salt costar Liev gushed in July 2010 about their kids' get-togethers during filming on their New York set: "There were playdates which were amazingly fun! We were playing shoot-ups inside the studio, and [our kids] were having squirt-gun fights out in the lot."
Kingston Rossdale & Ruby Maguire
Awww, Gwen's son and Tobey's daughter share a sweet moment in a Beverly Hills park back in February 2010. Too cute!
Kingston Rossdale & Romeo Beckham
Sports and rock royalty collide as Gwen 'n' Gavin's eldest son snacks with Posh 'n' Becks' kiddo during a playdate back in February 2009.
Nicole Richie & Harlow
It's party time! Nic totes her adorable daughter to Honor Warren's 3rd birthday party