"High School Musical" sensation Ashley Tisdale fell down a fight of stairs while in concert -- and "Extra" has the video!

The tape, however, is not what it seems. It's all for Ashley's new OMG campaign with Degree Girl. The Tizz sat down with "Extra" to break news for "High School Musical 3," including a cameo by Johnny Depp, a lunch date with Simon Cowell -- and lots of rehearsing!