Fathom defines noir as: "coined by French newspapers to describe the dark, bitter moods portrayed by American filmmakers in the early 1940s"
The article (one of many freely available in a good mix of subjects) goes on to talk about the background, the mood of the time and in-depth on five films - from The Maltese Falcon (1941) to The French Connection (1971)
And on that note - we just picked up the second CSI game; Dark Motives. Slightly interactive show - good fun, but not really all that challenging... mostly about finding the right spot to click... that's why we waited until it ended up as Ubisoft Exclusive.
