http://www.themoviebox.net/trailers/harrypotter3/
there you go.
I love the books, this one is my favorite of the 5 so I'm hoping they do a good job. I like the movies ok, but they are nothing compared to the books. I wouldn't say all the kids are bad. I think Harry is pretty cheesy, but the kids who play Ron, Hermione and Malfoy are great.