Los Angeles - College Tonight, an online social network that promotes off-line social interactivity among college students, said on Thursday that it has signed Lauren Conrad, of MTV reality series "Laguna Beach" and "The Hills," as its national spokesperson. Financial details of the deal were not disclosed. "Lauren has one of the most mature brands in young Hollywood and is a positive role model for young adults," said College Tonight CEO Zachary R. Suchin. "Her affinity for fashion and everything socially fresh is fluidly synergistic with College Tonight's efforts."