Dancing with the Stars: Meet Season 13's CompetitorsDavid Arquette, Kristin Cavallari, Nancy Grace, Chaz Bono and more will step into the ballroom on Sept. 19

ROB KARDASHIAN

Fresh from hitting the dance floor at his sister Kim's wedding, the reality star, 24, says he's going to concentrate on having fun. "Whether I fall or embarrass myself, I don't care," Kardashian says. "It's fun. It's entertainment. It's a challenge and I'm into it."