I've got my towel and my babelfish and have just got back from seeing the movie. I'm happy to say that its fabulous!
Even if there are some book deviations (I'm about to read em again, its been YEARS), they really captured the humor, profundities and the spirit of the book and Douglas himself. Apparently some things added or changed had actually been his idea.
I only have two probs. One is making Trillian such a love interest for Arthur. I don't know, I'll have to see it again and see if it really IS that bothersome or if I just know that it wasn't like that in the book and need to get over it.
Sam Rockwell was great as Zaphod (the rest of the cast was excellent as well) but I have to say I would rather he had two heads at once. The flipping up is actually pretty effective and freaky and funny, but I still think I would prefer it with just two side by side.
All in all a fantastic movie! I may even see it again tonight.