Star Tracks - Monday, May 26, 2008

Blake Lively and real-life love Penn Badgley spend the holiday in good company as they stroll together Monday through New York's West Village.The pair's costar, Lydia Hearst, tells PEOPLE of the couple, "They have just as much chemistry on set as off. "

See photos from the couple's romantic Mexican vacation.

Ashlee Simpson blows hubby Pete Wentz's cover as he playfully hides while leaving a friend's party on Monday in Los Angeles. The newlyweds just returned from a trip to New York after honeymooning in Turks and Caicos.

See more of your favorite stars in masks!

Before heading out west, Ashlee Simpson makes a post-honeymoon pit stop in New York City on Friday and squeezes in some shopping.

Is he working off his dinner? Owen Wilson speeds away on his bicycle following a meal with friends Sunday at New York's Bar Pitti.

Pamela Anderson hangs out with ex-husband Tommy Lee (left) and her sons (not pictured) on the beach in Santa Monica on Monday – but it's not all fun in the sun. The actress was filming her upcoming E! reality show, tentatively titled Pamela.

Ashley Tisdale and her pup Maui strut their stuff while out for a walk Monday in Los Angeles.

Beyoncé Knowles leads the way as she and husband Jay-Z leave the Palm Beach Casino in Cannes on Friday.

Dancing with the Stars pro Karina Smirnoff – who previously denied that she and beau Mario Lopez had split – seems to prove her point Sunday, sitting on top of the world (or Lopez's shoulders, at least) while frolicking in Miami.

Julia Roberts mixes business with pleasure while filming scenes for Duplicity in Rome on Monday. The actress, who's shot scenes in New York for the same film, was spotted kissing husband Danny Moder (not pictured) in between takes.

After spending time in Austin and smooching at a party in Cannes, Kate Hudson and Lance Armstrong take their new romance to Monaco, where they enjoyed a boat ride Sunday.

Kristi Yamaguchi waves the green flag to get the 92nd Indianapolis 500 under way on Sunday. "I'm very excited," the Dancing with the Stars winner told PEOPLE of being the first woman to start the race. "It's a huge honor."

Hilary Duff goes back to school Thursday, visiting Florida's Boca Raton Elementary School, where she kicked off the Blessings in a Backpack program, a non-profit organization that provides food for children and families in need.

Uma Thurman looks in need of a hand Friday on the New York City set of Motherhood. The actress plays a mom facing the challenges of planning her daughter's sixth birthday party in the comedy.

Another day, another stunning look! Michelle Williams glows with costars Catherine Keener and Samantha Morton at the premiere of Synecdoche, New York Friday in Cannes. Earlier, the actress premiered another film, Wendy and Lisa, at the festival, telling reporters, "It actually does feel kind of special to have two films at the same time."

Welcome to Fleet Week! Denise Richards, in town to promote her new reality show Denise Richards: It's Complicated, finds herself in the company of a few well-suited sailors, stopping for photos outside her hotel in New York City on Friday.

Rooney guitarist Taylor Locke keeps in touch with girlfriend Mischa Barton during a Thursday night out at The Met Bar in London.

Nicky Hilton prepares her windup during the opening ceremony of the Korean Baseball League Friday at the Jamsil Baseball Stadium in Seoul, where the LG Twins took on the Kia Tigers.