05/17/2010 at 01:00 PM EDT
bid farewell to her popular Disney series Hannah Montana
with a casino-themed bash at h.wood, an L.A. lounge. Joined by her castmates, including Emily Osment
, the actress was running around, dancing and singing along as the deejay spun songs like her hit "Party in the USA." Revelers also enjoyed sushi, hot dogs and fries and a doughnut cart. As for special drinks, guests sipped on blended iced tea. Will Smith
also briefly stopped by to drop off his kids, Willow and Jaden.
, standing in line at the concession stand at L.A.'s ArcLight Theater before catching a late-night showing of Iron Man 2
with a male pal. The casually-dressed actress picked up a Dove ice cream bar before taking seats in one of the back rows of the balcony. But the ice cream may have proved more enticing that the movie: Theron and her pal snuck out of the theater well before it ended.
Just before 1 a.m. on Saturday, Drew Barrymore
and some pals were spotted enjoying experimental musician Flying Lotus
' set at L.A.'s Echoplex. Barrymore and her friends were led up to the stage, where they watched the concert from the side.
, chatting over dinner and rose champagne at Mr. Chow in New York after performing at Carnegie Hall.
"She was very relaxed, stayed late into the evening and seemed to really unwind," a source says.
Also in New York: Taylor Swift
shopped with friends at Rugby Ralph Lauren downtown. The singer left with three large bags of clothes and even walked out of the store wearing one of her new purchases: some sunglasses.
By REAGAN ALEXANDER, ANDREA DESIMONE, JENNIFER GARCIA, JESSICA HERNDON and LINDA MARXCouples Watch: Jen Garner & Ben Affleck Spend Family Time in Louisiana >