Lindsay Lohan Photo by: INFGoff
Caught in the Act! | Lindsay Lohan
• Lindsay Lohan, smoking a cigar as she pulled up in a white Cadillac Escalade to British magazine publisher Jefferson Hack's birthday party in New York City. (Hack is the father of Kate Moss's 3-year-old daughter Lila.) Inside the fete, Lohan – who's been a rowdy party guest lately – played nicely with others and mingled with Sienna Miller, Michael Stipe and Helena Christensen.

• Kevin Federline, penny-pinching at New York City store Lounge. After asking for a price check on a $125 Howe T-shirt, he put it down and left the store empty-handed.

• Jessica Alba, taking Tae Bo classes at the Billy Blanks World Karate Center in Sherman Oaks, Calif. The actress – who also has a regular personal trainer – was sweating it out with the rest of the class.

• American Idol star Ace Young, Kelly Rowland and Serena Williams, checking out a performance by rapper T.I. at a pre-BET Awards party at the House of Blues in West Hollywood. Meanwhile, Chris Brown, danced to his own hit single "Run It" at a pre-BET bash he hosted at the L.A. Adidas Original Store. Ice Cube, Nick Cannon and Tyrese Gibson were among the hungry partygoers who feasted on In-N-Out-burgers served from a truck parked outside.

• Adrian Grenier and his Entourage costars, shooting a scene at hip new West Hollywood steakhouse and lounge Republic.

Tim McGraw and Faith Hill Photo by: Kevin Mazur / WireImage
Caught in the Act!| Faith Hill, Tim McGraw
• Faith Hill and Tim McGraw, joking with each other onstage ("You see what I have to live with every night? Try singing with that," quipped McGraw) at the Samsung Four Seasons of Hope Dinner at New York City's Tavern on the Green. The couple, who also sang, introduced their new nonprofit, Neighbor's Keeper Foundation, which assists victims of natural disasters. Later, they hobnobbed with former New York City mayor Rudy Giuliani and golf legend Arnold Palmer. "They were like little kids," a source says of the excited couple.

• Tobey Maguire, dining with girlfriend Jennifer Meyer at New York City eatery Serafina. The friendly couple left a generous tip after noshing on spaghetti with lobster and ravioli.

• Gavin Rossdale, supporting his "very dear friend" designer Ozwald Boateng at a bash at the Museum of Television and Radio in Beverly Hills for the Sundance Channel series House of Boateng. The new dad stepped out without wife Gwen Stefani. Also making the scene: Laurence Fishburne and Joy Bryant.

• By MARK DAGOSTINO, VANESSA DIAZ, MAUREEN HARRINGTON, JESSICA HERNDON, AMY ELISA KEITH and MICHELLE TAN