Two stoners drive about Los Angeles getting into scrapes, while they look for work. Christian Bale is yang - he's an aggressive, confrontational combat vet, who wants to work for the Police. Freddie Rodriguez (the cute little embalmer from Six Feet Under) is yin: he's reactive, soft hearted and thoughtful.
This film consciously repudiates the Hollywood three-act structure, which is great, but you do notice that it's missing. That is, you can't orient yourself in genre or plot-structure, so you don't know what events are important or what the emotional flow is. Obviously this is supposed to reflect the experience of the two guys.
Two examples - Bale needs to pass a urine test to get a job. The action around this is farcical, with straight-forward jokes in it. As this was early on I was thinking 'Oh, this is going to turn into a stoner comedy' but then it didn't. Later they are in a bar and a man is killed. It's shocking, but they run away, and there is no follow-up to the event, you don't hear any more about it.
Linked to this is the way Bale's behaviour, and with it the kind of film he belongs in, changes when he is at his job interviews. He switches from Keanu-style 'hey wassup dude' to this 'Sir, yes, sir' Marine vet act. I think this is interesting because in real life we do behave as if we are in different films as we go through the day.