I was gonna write up some thoughts on Little Miss Sunshine, but Laurie Toby Edison of body impolitic said pretty much what I would've.
As she notes, to talk about the part I'd (also) wanted to talk about--some rather pointed irony about the grotesque kiddie beauty pageant--inevitably spoils the ending. So I'll just say: if you don't mind spoilers, or if you've already seen it, go check out what she has to say. I'll wait here. The rest of you: it's worth seeing.