Book or movie?

Boys - we are currently approximately 2/3 through our first class novel of the year.  As a teacher I strongly believe in having a book 'on the go' as a class.  The Phantom Tollbooth has been a fantastic lighthearted starter for the year - some would say it is a classic, some would say it baffling and childish (it is a children's book I guess), most would say entertaining in some way.  A couple of weeks ago we had a look at part of the 1970 movie version. I would like you to watch the rest in your own time and finish it by the end of next week (P List time? BYO earplugs).  What did you make of the movie version?  Would you have preferred NOT to see it?  Did it add any value to your understanding and enjoyment of the book?  What liberties did the movie writers/directors/producers take with the story?  Did it 'work' for you?  A few of you (especially yr 8s after having had the novel read to you last year) have seen Life of Pi.  I have not seen it (I probably will when it is released on itunes) but will not be too worried if I don't.  To me the novel was the door to creating a picture in my head.  I believe most books can be recreated by the inner writer/director/producer.  Some add value, others do not.  The Hobbit movie adds value (to the book) for me.  If you have seen it, did it do the same for you?  What is another book/movie combination you have enjoyed?  Can you name one where you would rather not have watched the movie?  Or, rather, not have read the book?