Daniel Radcliffe (Harry Potter/all four of them) Warwick Davis --> Wicket the Ewok
Johnny Damon of the Boston Red Sox.
I was always under the impression that he was supposed to be the teacher. But as I've listened to it more and more, it definitely is not his voice. I think it was just an urban legend. As for the principal... interesting, never heard that one before. Be cool to find out for sure.