09/30/2011 at 10:00 AM EDT
and Heidi Klum
had a girls' night out, partying with a group of friends at Beacher's Madhouse inside the Hollywood Roosevelt Hotel
until nearly 2 a.m. The gal pals sat in a back booth and sipped champagne, according to one onlooker. Bullock, in particular, "had a smile on her face the whole night" and danced to songs including The Clash's "Rock the Casbah" and AC/DC's "You Shook Me All Night Long," the eyewitness said.