It's a great film, built entirely around his album of the same name. They both came out last year. It bored me at first, but then before I knew it, I was totally engrossed.
Here's some commentary from a review. I don't have time to write my own.
"Greendale is the story of a small fictional seaside town in California and specifically, the Green family. There's the activist daughter Sun Green, the cop-killer cousin Jed Green and grandma Thibodeaux. My favorite is the cantankerous Arius grandpa Green who tries to scare off the invading media hordes from his property with a shotgun.
On Greendale, Young's themes are environmental exploitation, specifically the Bush administration's plan to exploit the pristine wilderness of Alaska for oil exploration and extraction; the intrusive nature of the media; a government increasingly obsessed with surveillance of its citizens; and Young's familiar themes of family, love, hope and freedom. While there are no hit singles, the songs are for the most part well constructed and have a tight, cohesive feel that dovetails perfectly with the album's themes. The closing number 'Be The Rain' is a classic rousing-fist pumping anthem reminiscent of Young's 'Rockin' In The Free World'. Here Young sings, "Save the planet for another day/Attention shoppers, buy with a conscience and save/Save the planet for another day/Save Alaska. Let the caribou stay/Don't care what the governments say/They're all bought and paid for anyway/Save the planet for another day/Hey Big Oil, what do you say?"
While Young offers no solutions to these very real issues, he at least attempts to raise awareness and encourage participation: 'You can make a difference; if you really try... We got a job to do. We got to save Mother Earth'. On "Grandpa's Interview", Young rails against the media: 'TV crews and cameras/They wanted to interview Grandpa on the porch/They came through the gate and up on the lawn/Knocking' down Edith's tiki torch/Grandpa saw them there/Looking through the Venetian blinds/Those people don't have any respect/So they won't get any of mine/I ain't gonna talk about Jed.../
I don't watch channel 2 or 6 or 9/I don't have time to talk that fast/And it ain't my crime. It ain't an honor to be on TV/And it ain't a duty either/The only good thing about TV/Is shows like 'Leave it to Beaver' /Shows with love and affection/Like mama used to say/A little Mayberry living/Can go a long way."
http://www.6moons.com/worldmusic/greendale.html