Access Star Sightings: April 4 - 10, 2009

Robert Downey Jr attends a pre-production press conference for 'Sherlock Holmes', at the Freemasons Hall, on October 1, 2008 in LondonGetty ImagesAccess Hollywood

LOS ANGELES, Calif. -- On Saturday, April 4, in LA: Amanda Seyfriend and "Mama Mia" co-star Dominic Cooper shopping at American Rag... Jake Gyllenhaal and Reese Witherspoon , Sting and Trudie Styler, Gwyneth Paltrow and Chris Martin , Ben Stiller and Christine Taylor and "Iron Man 2" director Jon Favreau in attendance at Bond St. at the Thompson Beverly Hills hotel for Robert Downey Jr.'s birthday.

On Sunday, April 5, in LA: Dixie Carter and Hal Holbrook in church in Beverly Hills... Sarah Silverman at Hugo's in West Hollywood, gushing over twin 8-month-olds.

VIEW THE PHOTOS: Week's Best Star Sightings, April 4 - 10, 2009

On Monday, April 6, in Las Vegas: Lindsay Lohan 's ex, Samantha Ronson , enjoying a solo post-break-up dinner at Strip House at Planet Hollywood Resort and Casino.

On Tuesday, April 7, in LA: "Dancing With the Stars" alumni Shannon Elizabeth and Jeffrey Ross making separate appearances in Runyan Canyon.

VIEW THE PHOTOS: Robert Downey Jr.

On Wednesday, April 8, in LA: "Castle" star Nathan Fillion taking an evening hike with friends in Fryman Canyon... Dita Von Teese in full makeup, buying groceries at Trader Joe's in West Hollywood.

And in London: Jason Segel and Paul Rudd at a VIP screening of "I Love You, Man" at the Soho Hotel.

On Thursday, April 9, in Miami: Josh Hartnett at the Florida Room, where he checked out rock band Awesome New Republic.

VIEW THE PHOTOS: Amanda Seyfried

And in LA: Amy Poehler looking glam in an LBD at the premiere of her new show, "Parks & Recreation"... Former "Laugh-In" star Jo Anne Worley at the Toluca Lake Post Office, checking her P.O. box.

On Friday, April 10, in San Diego: Debra Messing with her family at the SeaWorld sea otter exhibit.

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