The fashions, trends, and slang may change, but few experiences are as timeless and universal as the social rollercoaster of being a teenager! High School Musical star Ashley Tisdale headlines

Following are the new actors and characters that will join CBS's hit series this fall in regular, recurring and guest starring roles.

The Lost Room, a thrilling mini-series event that previously aired on the Sci-Fi Channel on December 11, 2006, features an all-star cast including Peter Krause, Julianna Margulies, Margaret Cho, Roger Bart and Kevin Pollak.