Star Tracks: Monday, October 25, 2010

Alert the authorities – Snooki's gone missing! The Jersey Shore star (a.k.a. Nicole Polizzi) gets in the Halloween spirit while trying on costumes in Paramus, N.J., on Saturday.

This Housewife's got a need for speed! Eva Longoria Parker revs up the crowd at Saturday's Rally for Kids with Cancer Scavenger Cup brunch at the Hollywood Roosevelt Hotel.

Madonna makes her way through New York's JFK International Airport with her two little ones, Mercy, 4, and David, 5, Sunday night for a trip back to the States.

See more stylish celebs taking flight!

Yankee fans – and exes of BFFs Justin Timberlake and Trace Ayala – Cameron Diaz and Joanna Garcia keep their friendship going strong, linking up for a night out with Glee's Matthew Morrison (not pictured) at Hollywood's Bardot nightclub Saturday night.

Could a duet be in the works? Justin Bieber and Mark Wahlberg have a meeting of the minds at Variety's 4th annual Power of Youth event in Hollywood on Sunday.

Justin Timberlake, Christina Aguilera and Diddy at a special concert to benefit Shriners Hospitals for Children in Las Vegas on Saturday. Later that night, newly single Aguilera took her crew of dancers and friends to TAO Las Vegas where she stayed until nearly 3 a.m.

Halle Berry and Olivier Martinez arrive hand-in-hand Saturday at the 32nd annual Carousel of Hope Ball benefiting the Barbara Davis center for childhood diabetes at the Beverly Hilton Hotel.

David Beckham takes his sons – Romeo, Cruz and Brooklyn – for a day of male bonding at the Kinect for Xbox 360 launch party in Beverly Hills on Saturday.

Prince William and girlfriend Kate Middleton make a striking pair while attending a friend's wedding in the English countryside on Saturday.

Days after glamming it up with famous friends in Hollywood, Kate Hudson is back to basics Friday, cruising around New York's East Village with her chauffer – er, son! – Ryder, 6.

Lady Gaga leaves her London hotel in a gauzy blush-pink confection with black piping, dip-dyed tresses, kooky optics and gravity-defying platforms on Friday.

Gym, tan ... Goofy? Jersey Shore star Paul "DJ Pauly D" Delvecchio teaches Disney's dapper dog how to fist-pump Friday during a visit to the Magic Kingdom in Lake Buena Vista, Fla. The show returns for a third season in January.

Coffee break! Gossip Girl stars Leighton Meester and Penn Badgley warm up with some hot drinks on Friday while stylishly filming scenes together in New York City.

No gutter balls here! Mad Men's Jon Hamm shows his strength Thursday night while bowling for a cause during the 13th annual Project ALS benefit at New York City's Lucky Strike Lanes amp Lounge.

Spotted! Reality starlet Holly Madison shows her wild side Thursday in a sexy leopard-print mini at the Crazy Horse Paris cabaret show at Las Vegas's MGM Grand Hotel amp Casino.

Heather Locklear does some heavy lifting Thursday, pushing a cart full of bulging suitcases at Vancouver International airport.