My review of The Hunger Games audiobook was published at Prometheus Unbound recently. I also commented on Mathhew Alexander's review of the film by adding some comparative perspective to the book. Tying all of this together, I just noticed Sam Staley's comments on the film versus the book over at the Independent Institute blog.
The executive summary of all of the above is that the book brought across a much more radical pro-liberty, pro-individualism message than the film does. Traces are still there, but the deepest messages and themes I found in the book, such as the quest for natural win/win cooperation even in the face of the state's artificial win/lose and lose/lose games, have been weakened considerably. The exteriors have been recreated quite skillfully in the film; not so much the interiors. It is still a decent film, but much beyond it, especially in terms of deeper moral and political content, can be gained from the book.