Competition in School?

I use competition in my classroom to liven things up. We often have to pass out a class set of text books to the students, and I use a competitive method to keep it interesting. Each class competes against the others for the best "Book Speed" and the winning group gets a prize. I have never seen students so excited to get their text books! As long as they are civil and encouraging to one another, I can't see what the problem with competition is. It improves behavior, challenges them, and encourages teamwork. Why can't it be the same with the schools and districts? I was surprised and fascinated by this video, Stupid in America, a John Stossel 20/20 special. Check it out. What do you think?
--Mr. Riedl