Star Tracks: Monday, October 31, 2011

Live! co-host Kelly Ripa and singer Nick Lachey do their best impressions of now-divorcing couple Kim Kardashian and Kris Humphries during the N.Y.C. talk show's annual Halloween extravaganza Monday.

Leonardo DiCaprio keeps it monochromatic in a three-piece suit Saturday while shooting scenes for The Great Gatsby in Sydney, Australia.

Clad in an oversize sweater, Jessica Simpson once again flaunts her new curves while locking hands with fiancé Eric Johnson in Beverly Hills on Sunday.

Isn't she lovely? Amy Adams holds tight to her expressive tot Aviana, 1, during a Friday outing to Mr. Bones Pumpkin Patch in Beverly Hills. See more stars in costumes here.

Now you can let go! A well-dressed Josh Duhamel receives a giant bear hug in Los Angeles Saturday at the 18th annual Dream Halloween benefit to support children and families affected by AIDS.

A day after playing party hostess, Leighton Meester bundles up in a color-coordinated ensemble – including a fascinator! – to shoot Gossip Girl in New York on Friday.

A freshly faux-hawked Justin Bieber arrives on set for a Proactiv shoot in Los Angeles on Friday.

Bethenny Frankel hits the streets in a pair of towering heels Friday while out in Beverly Hills with daughter Bryn, 17 months.

Newlywed Nikki Reed trades her offscrreen husband for on-screen sibling Jackson Rathbone at Sunday's Rome International Film Festival premiere of The Twilight Saga: Breaking Dawn – Part 1.

No doubt about it, Gwen Stefani is a fairy tale princess at a Halloween party in Los Angeles on Saturday night.

Christina Aguilera boasts about her team of singers for the upcoming season of The Voice on Friday in Los Angeles.

Fun in the sun! Gisele Bündchen rocks that supermodel body and keeps 22-month-old son Benjamin close to the hip during their Caribbean vacation.

A pregnant Hilary Duff – who recently revealed she's expecting a baby boy – leaves her pilates class in tip-top shape Friday in Toluca Lake, Calif.

Anne Hathaway pauses from her busy social schedule, opting for a quick workout in Brooklyn, N.Y., Friday.

Lady Gaga adds a colorful splash to her wardrobe during a press conference Friday in New Delhi, India. The pop star is in town to perform Sunday at a Formula One afterparty.

Joseph Gordon-Levitt and Christian Bale answer the call of duty Friday, patrolling the fictional streets of Gotham City while on the N.Y.C. set of their upcoming action flick, The Dark Knight Rises.

After spilling the beans on her newlywed living situation, a causal Kim Kardashian leaves her home on Friday in Santa Monica, Calif.

Justin Bieber gets tongues-wagging thanks to his vintage Rolling Stones concert T-shirt, while out and about Thursday in L.A.