For those who loved the book, beware: the movie, while true to its source sometimes, takes great liberties at times, changing its tone from that of book considerably. Standing alone, its an off-the-wall crazy sci-fi flick that's difficult to follow, but is funny, if you like british humor (I do, and that's why I gave it as much of a score as I did). Its main faults as a movie itself is that it is so uneven and confusing. I remember that's how the book was as well, but Douglas Adams made it work, and the book was more consistent in its humor.

The things the movie added that weren't in the book I found to generally detract from the movie rather than add to it. The additions were generally more stupid and less witty than anything in the book and, as someone who has read the book and has expectations, I found it grating to watch these parts.

Even the depictions that were true to the book sometimes bothered me, perhaps because I'd imagined them differently. One thing about the book is that the character descriptions are rather vague, leaving it up to the reader's imagination. So all of us might have imagined a totally different looking Zaphod or Marvin (these were the main characters that bothered me). It makes sense, though, that Zaphod's appearance was made to look more human, but his second head I found extremely disconcerting. Marvin though...I was completely disappointed. His large, clumsy design might have worked if he were smaller, say 4 feet tall, but his huge and completely inhuman appearance was hard for me to stomach as I had imagined him as more of a 'normal' looking android. And as much as I loved Alan Rickman's voice and thought it fit Marvin, the script didn't include the clever things that made up Marvin's overwhelmingly depressing character; rather they simply had him repeat the same thing over and over, such as "we're doomed" or "I'm better off dead". In the book Marvin is endearing and hilarious and you always feel bad for him because of the predicaments he gets into; in the movie, he's an annoying side character who is entirely disposable and out of place.

The long and short is, the Hitchhiker's Guide to the Galaxy probably isn't meant to be made into a movie because of its tangential and random style. Adams' goofy whimsy of cut scenes and tangents that once in a while meet up together to contribute to the story simply doesn't translate coherently onto the silver screen. Read the book if you haven't already, its worth the extra time to do so rather than wasting 2 hours of your life being confused by this movie.