From the movie:
Linda Cardellini
Matthew Lillard
Freddie Prinze, Jr.
Sarah Michelle Gellar (Read the interview!)
Writer - James Gunn (Read the interview!)
Director - Raja Gosnell
Scooby Voice - Neil Finnegan
Voodoo Maestro - Miguel A. Núñez Jr.
Mary Jane - Isla Fisher

Others:
Mae Whitman and Alia Shawkat
Michelle Trachtenberg
Shannon Doherty
Cindy Ambuehl
Eva LaRue Callahan
David Fury
Jeri Ryan
Gene Simmons
Lindsey Sloane