Celebutante number 2 is set to serve time! Yup, Nicole Richie plead guilty to driving under the influence and was sentenced on Friday to serve four days in city or county jail. (She got credit for a fifth day because she served six hours after being arrested.) But she'd better hurry -- she must serve her time by September 28. Plus, with those horizontal stripes and that pregnant belly, she's gonna look like a watermelon!

Nicole will also have to pay a fine of $2,048, take a 21-day alcohol education course, and be on probation for three years. Plus, the commissioner told Nicole that if she ever drove drunk again and actually killed someone, she could be charged with murder instead of manslaughter.

At the sentencing, Nicole was "stoic and serious, but not emotional," an insider tells TMZ. She was accompanied by BF/baby daddy, Joel Madden. "The judge did not give her special treatment," Los Angeles District Attorney spokesperson Jane Robison tells Us Weekly. "She is given the same option that any person who pleads guilty to this charge to serve in city or county jail."

Do we smell a reality show in the making?!