Heidi Klum, Lauren Conrad Hit Us Weekly's 'Hot Hollywood' Bash

Lauren and Heidi partied together last night in Hollywood.

Lauren Conrad and Heidi Klum, that is.

The two were among the throngs of celebs -- including Gerard Butler, Danity Kane, Nicky Hilton, Rumer Willis, and Conrad's former fling Stephen Colletti -- who hit Us Weekly's Hot Hollywood bash at Beso restaurant Thursday.

(See what the stars wore here.)

Clad in Catherine Malandrino and Christian Louboutin shoes, Conrad (who arrived with pal Lauren "Lo" Bosworth) said she opted not to wear a piece from her new collection.

"I've been wearing it every single night so I was changing it up tonight," she told Usmagazine.com.

Conrad stayed close to Bosworth at the bash -- at point she told her, "Don't lose me!" -- but she also had some face time with Spencer Pratt's sister, Stephanie.

(So where were Heidi and Spencer? "I think they missed their flight," Stephanie told Us. "I was going to come with them!")

"The Hills" cast weren't the only TV stars at the bash.

The "Dancing With the Stars" crew -- including Cheryl Burke, who wore Eduardo Lucerno, and Karina Smirnoff -- also boogied.

Klum -- Us' Style Icon of the Year -- wore a dress designed by last season's "Project Runway" contestant Rami Kashou.

Of being honored, Klum told Us, "It's a great compliment to my whole team. As you know, everyone who sets foot on a red carpet does not get dressed and do their hair and makeup by themselves!"

Of course, the night wouldn't have been complete without a fashion emergency.

Lisa Rinna told Us she initially planned to wear a white frock to the bash.

"We went to our store, and he decided to touch up the counter with a little pen, and I went up against the counter and the black pen came off on the white dress!" she said.

"I had to pull this right off the rack at Belle Gray [her clothing line]!"