John Hawkes plays Mark O'Brien (this is based on the life of the real Mark O'Brien) who is paralyzed from the neck down and living in an iron lung (the results of polio). At the age of 38, he decides he wants to lose his virginity after he researches and writes an article about sex among the disabled. He receives unlikely support from his priest (William H. Macy, particularly charming) and his own assistant (played by Moon Bloodgood), and starts to see sex surrogate Cheryl Cohen-Greene (Helen Hunt).
The movie has a great deal of frank talk about sex, and a fair bit of naked Helen Hunt. Which is fine, but it's a successful movie based on the characters, the actors, and the script, all of which are both funny and very good.