Star Tracks - Monday, May 5, 2008

Newly engaged to Ryan Reynolds, a glowing Scarlett Johansson shows off a sparkling diamond ring while posing – in an ivory Dolce amp Gabbana dress – with designers Domenico Dolce and Stefano Gabbana at the Metropolitan Museum of Art's Costume Institute Gala in New York City.

Just days after news broke that Mariah Carey tied the knot with Nick Cannon in a surprise ceremony, the newlywed singer emerges to do a little sunbathing (and honeymooning?) at her beachfront estate in the Bahamas on Saturday.

Tori Spelling and husband Dean McDermott have their hands full as they leave a baby shower thrown in their honor at West Hollywood's Le Petit Hotel on Sunday.

Ashton Kutcher and wife Demi Moore are fashionably coordinated while stepping out Sunday in New York City. Kutcher is in town promoting his latest movie, What Happens in Vegas, with Cameron Diaz.

Reese Witherspoon hits the pavement for the Avon Walk for Breast Cancer in Washington, D.C., on Sunday. The actress, who's the global ambassador and honorary chair of the Avon Foundation, joined 3,500 walkers in the two-day event, which raised $8.1 million for breast cancer research.

He's not having a ball – yet! George Clooney and girlfriend Sarah Larson (not pictured) arrive in New York on Sunday. The couple is expected to attend Monday night's Metropolitan Museum Costume Institute Gala, which the actor is co-chairing this year.

She's a little bit country, a little bit rock 'n' roll! Carrie Underwood works the crowd Sunday while headlining the Stagecoach Country Music Festival in Indio, Calif. The singer performed her hit "Before He Cheats" – and even covered Guns N' Roses' "Paradise City."

A beaming Robert Downey Jr. enjoys the best seat in the house, sitting courtside as the Los Angeles Lakers face off against the Utah Jazz Sunday at the Staples Center. And the actor had plenty to smile about: apart from the Lakers' win, his film Iron Man grossed more than $100 million over the weekend.

Go, speed racer! Clive Owen is seriously light on his feet as he films a scene for the dramatic caper Duplicity in New York City on Sunday. The movie re-teams the British actor with Julia Roberts, his costar in 2004's Closer.

Sean 'Diddy' Combs hangs tight with pal Cameron Diaz at his From Harlem to Hollywood bash in Beverly Hills on Friday. Earlier that day, the music mogul received his star on the Hollywood Walk of Fame.

Katie Holmes and Tom Cruises are spotted leaving their New York City hotel Saturday with one cuddly bundle, daughter Suri, 2.

They're off again! An expectant Angelina Jolie and partner Brad Pitt take daughter Zahara for a helicopter ride Saturday in the South of France. The couple are expected to remain abroad to attend the Cannes Film Festival, May 14-25.

Showing their senior class solidarity, High School Musical 3 stars Ashley Tisdale, Zac Efron, Vanessa Hudgens, Monique Coleman and Corbin Bleu return to the spotlight Friday at a press conference in Salt Lake City, Utah, to promote the third installment of their musical mega-hit.

With sister Britney back in Kentwood, La., a pregnant Jamie Lynn Spears stops by a friend's place to say hello to some new puppies in McComb, Miss., on Thursday.

Rihanna gets up close and personal to rocker Adam Levine during a Los Angeles video shoot Friday for the remix of Maroon 5's "If I Never See Your Face Again," hitting the airwaves on May 13.

With a bright bandana and music in his ears, Snoop Dogg smirks for photographers Thursday as he makes his way through the Los Angeles International airport.

Jessica Alba, who told PEOPLE recently that she's frantically getting her house baby-ready, takes time out to visit a group of students at L.A.'s Thomas Riley High School.

Holy prints! You definitely can't miss Paris Hilton as the hotel heiress picks up a new perch for her pets at L.A.'s Beverly Glen shopping center on Thursday.

It's a regular riot as Haylie Duff hangs backstage with Legally Blonde: The Musical actress Laura Bell Bundy on Thursday. Hilary's older sis is set to host the upcoming MTV reality show Legally Blonde – The Musical: The Search For Elle Woods, in which aspiring actresses will compete to replace Bundy in the Broadway show.