I've linked to this site once before, but Screen It has Christian-themed reviews of movies, where it itemizes all of the potentially objectionable behavior in a film. But it does so to such a detailed extent that it's really quite amusing.

There's not much for "March of the Penguins," but the listing for "The Aristocrats," which is a movie where a bunch of comedians all tell a dirty joke, is kind of funny. See here.

And they really itemize everything. Which may be unnecessary, because if this doesn't bother you, as a parent:

George Carlin does a particularly graphic bit about describing the nature of his watery excrement going into the narrator's wife's mouth and that he ate corn and nuts to provide some bulky objects. He then adds that a polyp threw off his aim, but most went in and that the wife gargled with and then swallowed the excrement.

Then are you really going to be bothered by:

We see Fred Willard with an unlit pipe.