A full length trailer for the upcoming animated film "Horton Hears a Who" has been released. It is based on Dr. Seuss' 1954 children's book and stars Jim Carrey as the elephant and Steve Carell as the Mayor of Who-ville.

The story is about an imaginative elephant, who hears a cry for help coming from a tiny speck of dust floating through the air. Suspecting there may be life on that speck and despite a surrounding community that thinks he has lost his mind, he is determined to help.

The film is scheduled to hit theaters on March 14th, 2008.