I've been meaning to put in a plug for This Film Is Not Yet Rated
, last year's documentary about the MPAA's "voluntary" rating system. As cultural criticism goes, this isn't especially far-reaching or ambitious—it's certainly not anything resembling a call to action—but I think the simplicity of the subject matter has a lot to do with the movie's charm. MPAA ratings are so much a part of everyday life we hardly notice them—but it turns out that when we take the time to look at them we discover some very strange things.
In particular, I can't recall anything aimed at a general audience that so effortlessly lays out our cultural hang-ups about sexuality in general and female sexuality in particular. Despite (maybe because of) the naughty bits, it'd be great in the classroom.