This is one of the most fascinating movies I have ever seen. It is about the extensive sexuality studies that Kinsey did during his lifetime. Much of his research in the movie was stuff I was familiar with. A lot of the stuff on women was stuff like clitoral vs. vaginal orgasms and anatomy and arousal. I didn't realize that Kinsey was the one who did all of the scientific studies that publicized that information, though. The movie is sporadically interrupted with tidbits from an interview with Kinsey (a fictionalized interview at least, I'm not sure how much of it was from an actual interview).
Kinsey is also the one who theorized that most people's sexuality falls on a continuum between heterosexuality and homosexuality. He believed that most people are a little bisexual at least. Personally, I am a six, which is homosexual. I can't say I've ever been attracted to a man. The theory is interesting, though.
The acting in Kinsey is fantastic. Laura Linney plays Kinsey's wife, a liberal woman who participated quite actively in Kinsey's research. She is excellent in this film, as is Liam Neeson who plays Kinsey.