Gwen Stefani, George Clooney and Diddy among stars in town

Tom Donoghue/www.donoghuephotography.com

No Doubt, with lead singer Gwen Stefani, kicked off its summer tour Saturday night, May 16, 2009, at Tiger Jam 12 in Mandalay Bay Events Center.

By Melissa Arseniuk (contact)

Monday, May 18, 2009 | 6:46 a.m.

Gary Newkirk / Tiger Woods Foundation

Gwen Stefani and Tiger Woods at the Tiger Jam XII After Party inside the House of Blues at the Mandalay Bay.

Gary Newkirk / Tiger Woods Foundation

Gwen Stefani and Tony Kanal of No Doubt perform during Tiger Jam 12.

George Clooney.

Star sightings in Las Vegas have undoubtedly been heating up as the temperatures have continued to rise.

In fact, celebrity-watchers didn’t have to wait until the weekend to see some famous faces around town.

Gwen Stefani, along with son Kingson Rossdale and No Doubt bandmates were spotted across town all week as they took in Cirque du Soleil shows in advance of the group’s performance at Mandalay Bay on Saturday.

George Clooney hosted a dinner party at the Hard Rock’s new steakhouse, Rare 120, on Thursday night to celebrate the wrapping of his latest flick, “Up in the Air,” which was filmed here in Vegas. Director Jason Reitman was among the guests at the table.

The cast of the soon-to-be-released Las Vegas-based comedy, “The Hangover,” was also in town this past weekend.

Heather Graham, comedian Zach Galifianakis and Bradley Cooper (“Wedding Crashers,” “He’s Just Not That into You”) were three of the cast members who participated in a private poker tournament at Caesars Palace.

Other members of the cast, including Ed Helms (“The Office”) and Justin Bartha, (“National Treasure”) and director Todd Phillips (“Old School”) also participated in the event, which supported Opportunity Village.

The cast was spotted the following day, too, as they enjoyed a group lunch at Spago.

Also on Friday, '90s rock band Everclear played a short set at LAX at the Luxor, while Seven Mary Three relived their glory days with a performance at Wasted Space at the Hard Rock.

The slightly more recent and heavier group, Staind also played for local rock fans on Friday, but their show was off The Strip and out in Henderson, at Sunset Station.

Earlier that day, Eek-a-Mouse visited the Hard Rock for a reggae-filled afternoon by the pool. Meanwhile, members of LMFAO caught some late afternoon sun with a performance at Wet Republic at MGM Grand.

After their gig, LMFAO headed over to the Palms to catch DJ AM, a.k.a. Adam Goldstein as the the still-new Friday night resident DJ spun his set at Rain.

The DJs enjoyed Ketel One vodka from their VIPO table and partied with a group of about 10 friends, which was said to have included cast members of MTV's "Real World Cabo."

Actress Gabrielle Union and Miami Heat pro basketball guard Dwyane Wade also enjoyed some Ketel One as they took in AM's set from a VIP table at Rain on Friday night.

Shannon Elizabeth and her boyfriend, Derek Hough of "Dancing with the Stars," were spotted grabbing a cocktail together at Blush at the Wynn.

And finally, "Tough Love" vixens Jacklyn Watkins and Taylor Royce hosted Friday night’s party at Jet.

Saturday involved a mixture of rappers and rockers, with Sean “Diddy” Combs at Wet Republic and Ja Rule at Pure at Caesars Palace.

While Diddy spent most of the afternoon lounging in his cabana, he took the time to mingle a little with his fans and gave a short performance, too, and performed a solo version of "Last Night" (his single with Keyshia Cole).

Gwen Stefani and her diverse and musically flexible group, No Doubt, kicked things into high gear at the annual Tiger Jam at Mandalay Bay – and the event’s namesake founder, Tiger Woods, put in an appearance, as well.

The 13th-annual concert was part of Woods’ ongoing do-gooding: The golfer’s namesake event supports youth empowerment initiatives through his corresponding namesake nonprofit, the Tiger Woods Foundation.

Tiger Jam also included impressive opening bands Paramore and The Sounds.

Also on Saturday’s musical docket, BB King played the House of Blues and heavy metal thrashers Helmet rocked Wasted Space.

Former NHL star Adam Oates was seen having dinner at Nove Italiano on Saturday night.

Also at the Plams, Barry Bonds and a large group of friends partied at both Playboy Club and Moon. The MLB free agent made time for fans who recognized him, and both signed autographs and posed for pictures throughout the night.

Two notable DJs were also in town this weekend to perform on Saturday night: Nick Warren played Perfecto at Rain at the Palms, and Linsday Lohan’s still-somewhat recent ex, Samantha Ronson, once again returned to the DJ booth at Privé.

Sunday saw two more techno sensations, including one of the world’s top-ranked DJs, Ferry Corsten, a.k.a. System F; and the woman who collaborated with esteemed DJ David Guetta on his international hit single, “Delirious,” Tara McDonald.

Corsten played Daylife Sundays at Wet Republic while McDonald performed at Tao Beach.

Former Rage Against the Machine guitarist Tom Morello’s new band, Street Sweeper Social Club, canceled its Las Vegas debut scheduled for Sunday night at Wasted Space.

No reasons were given for the last-minute cancellation, which was made less than 24 hours before the band was expected to take to the stage.

The group is currently touring with Nine Inch Nails and Jane’s Addiction, both of which are scheduled to perform at the Palms tonight.

Who knows, maybe Morello will pop by the Pearl tonight, either as a special guest performer or simply to see Trent Reznor, Perry Farrell, Dave Navarro and the rest of his tourmates perform on his day off.

David Rush and Rick Ross will also perform this evening, Rush at Jet and Ross at Privé.

Looking ahead, Ben Folds will play House of Blues tomorrow night, while renowned Dutch DJ Sander Van Doorn will play Body English.