Mischa Barton by Jamie McCarthy/ WireImage.com Mischa Barton by Jamie McCarthy/ WireImage.com

Calling into Ryan Seacrest's On the Air radio show, O.C. alumna Mischa Barton spoke openly about her Dec. 27 DUI arrest, saying, "I'm 100 percent responsible for my actions," and then adding, "I really am disappointed in myself."

Barton could not get into the particulars about what happened or her alleged state at the time she was pulled over, but seemed genuinely ashamed. "I don't know what to say about it except that I'm not perfect, and I don't intend to do something this stupid again." I think she just ruled out an O.C. reunion movie. Oh, wait....