oh my gosh, oswaldtheluckyrabbit, you are reading my mind today! I was just thinking about this film earlier today. I've been on a noir kick and have been enjoying the hell out of reading Chandler novels for the first time. This got crap reviews but you have to give it credit for being...unique.
I've been reading a lot of his books as well, and wondering how you'd do them justice in an adaptation. Chandler has an interesting technique where he tells you everything Marlowe sees, and how he sees it, but tells you very little of what he thinks and knows, so there's a great intimacy with the character without loosing dramatic tension.
First person POV is an interesting attempt, but it looses that sharp edge of Chandler's language.
Also, if anyone here hasn't read it:
http://www.en.utexas.edu/amlit/amlitprivate/scans/chandlerart. html
"The Simple Art Of Murder"
One of the great critical essays I've ever read, by Chandler about detective fiction.
I had to watch it for my film noir class in college. If you like the genre it's kind of essential I think, but it's a novelty. The joy of it is the innocence of the experiment.
This was actually pretty effective on me. I found myself starting to think like the character, especially because of the little touches like blowing smoke in the police officer's face.