I'm not usually one to recommend books in Oprah's Book Club, but hey, if it's a good story, why not? I got interested in this story after seeing the movie, which is usually backwards to most people's experiences. I have found that if I liked the movie, the book must have been really, really good. Hollywood usually does such a hack job making movies from books, but in this case they did a fairly nice job. The book and the movie follow the same plot except for a few twists that were developed, I'm sure, to keep the story moving.
Both the book and the movie are recommended. The movie has Natalie Portman going for it, so it's a no brainer for me. :P