Spotted!

After watching Britney Spears' last U.S. concert on her "Circus" tour in Las Vegas on Sept. 27, Lance Bass made a stop by the Mirage's Beatles Revolution Lounge weekly gay party, "Closet Sundays." The former N'Syncer was joined by a group of Brit's backup dancers and drank vodka cocktails while mingling with partygoers at the lounge. Earlier that night, Bass was pulled on stage by Spears while she performed "Breathe on Me" as the crowd of 12,000 went wild while the openly gay singer smiled and sang along.

George Clooney, his new girlfriend, Cindy Crawford and husband Rande Gerber having drinks at Whiskey Blue at W Los Angeles-Westwood hotel.

Tyra Banks eating lunch in the Gordon Ramsey restaurant “maze” at The London Hotel in NYC.

Harry Potter hottie Thomas Felton celebrating his birthday with a large group of friends at Prive Las Vegas at Planet Hollywood, dancing on his banquet to songs by Michael Jackson, Journey and Beyonce. Reveling with a chocolate and maraschino cherry decorated cake, the actor known as Draco Malfoy had a blast, despite texting with girlfriend and Harry Potter stunt coordinator Jade Olivia, who wasn’t able to attend all night!

Ginnifer Goodwin at NSF Clothing and GQ Magazine's Humane Society Benefit to Stop Puppy Mills at a home in the Hollywood Hills.

Mary J. Blige at the New Yorkers For Children Fall Gala at Ciprianis 42 New York in NYC.

Shannon Elizabeth and Derek Hough appear to be back together as they reunite for a night out at Playhouse Hollywood.

Melissa Joan Hart getting color, cut and eyebrow shaping at Prive Salon L.A.

Christina Milian and singer producer The Dream were at Sunset Plaza’s Buttercake Bakery for a private wedding cake tasting.

Mel B. using a SmokeStik in London.

Shannen Doherty getting her color done by Adam Scheib at Prive Salon L.A.

Susan Sarandon and Russell Simmons supporting leading human trafficking activist Somaly Mam at her Second Annual Benefit in NYC.

Mickey Rourke joined Leonardo DiCaprio, Kobe Bryant and Jeremy Piven at the Vitali Klitschko fight at the Staples Center in L.A. this past weekend, adorned with a special set of accessories. He had a Ukrainian flag in his hat and a Neuro Gasm in his pocket. The nutritional beverage is a favorite amongst celebrities and is designed to promote blood flow. Pretty appropriate for a boxing match!

Clive Owen at Hollywood hotspot MyHouse.

John Krasinski joined by friends David Schwimmer and Josh Charles during the after party for his film Interviews with Hideous Men at Su Casa in NYC.

Common and girlfriend Serena Williams joined by friends Talib Kweli and Queen Latifah headed to Bardot for “Lo Hi Fi.”

Deborah Gibson at What A Pair! 7 -- A Celebrity Concert Benefiting Breast Cancer Research at John Wayne Cancer Institute at St. John's Health Center in L.A.

Ali Landry hosting the Matters on Design VIP event in LA while enjoying the Rose's Cocktails hosted bar.