The Hitch-hiker's Guide to The Hitch-hiker's Guide

Back in the early eighties, my dad bought me Douglas Adam's remarkably funny trilogy, The Hitch-hiker's Guide to the Galaxy. Before long, I had huge portions of the novels committed to memory. I'd have to say that Hitch-hiker's was my Lord of the Rings and Star Wars all rolled together. I figure I've read the first three books maybe twenty times over the years. (Skip the last two: they read like they were written to pay a dentist bill. Especially Mostly Harmless, which wasn't.)
But the first three books are pure comedic gold, if you like dry Pythonesque humour. One of my favourite lines: "Nothing happened. And then, after a minute or two...nothing continued to happen."
In grade seven, our class put on a stage version...yours truly had a minor role as Prosser, the man who tries to convince Arthur Dent to let his home be bulldozed, about ten minutes before Planet Earth gets figuratively bulldozed.
In spite of the play and the high esteem in which I held the books, I never even considered the idea that they'd make a movie. I figured the whole thing was way too madcap for a film to do it justice.
It took them the better part of thirty years, but The Hitch-hiker's Guide to the Galaxy is now a Hollywood production. I saw it today. I'd give the movie about a six and a half out of ten.

The screenplay, partially penned by the late Douglas Adams himself, presents a damned-if-you-do, damned-if-you-don't scenario. The parts that are faithful to the novel lose a good bit of their humour when us Hitchhiker addicts see every joke coming a megaparsec off. (There was a guy behind me reciting just about every spoken Guide entry verbatim. I could have done so, but I'm not...quite...THAT much of a geek.) And the parts that depart from the book just jar. The whole Humma Kavula character and plot felt like a little scrap of soap that's been imperfectly grafted on to the bar.
All that said, the acting was very good throughout. Alan Rickman as the voice of Marvin the Paranoid Android is casting perfection.
I'm not sure what non-readers would make of this film. It captures the spirit of the book, but feels rushed in so doing, so those who haven't read the trilogy would probably be left with a giant HUH? at the end.
If you've read the book, you've probably seen the movie already--and if you haven't, you might not want to.
A sequel is all but certain and I for one can't wait to see what they make of The Restaurant at the End of the Universe, which is probably my favourite installment.