For a movie about a crack-addicted teacher falling apart while trying to keep a favorite student from falling under the influence of a suave crack dealer, Half Nelson is remarkably cheery and satisfying all the way through. Having taught in some similar classrooms, I don't think the portrayal of the school scenes is entirely true to life--I mean, he has what, like 12 students in his class? C'mon. Plus, they sit there and listen to him as he rambles on abstractly about history non stop. But still, all the kids act pretty naturally and, well, I don't know how to put it into words yet; it's just a great film.
At points, I wonder if it isn't almost romanticizing the bottomed-out life the teacher is living. He's a crack head, but he's a tortured artist, sleeping on a bare mattress with his little drawings scattered about and it almost comes across as a viable, hip, lifestyle. He wears cool sunglasses. You almost think that if his cat didn't die (not really a spoiler), he might have been able to keep things together. But again, despite this reservation, one of the best movies of the year for me.
The soundtrack is spiffy, too. I'd always wondered about Broken Social Scene, and now I know they're worth looking into.