Before Al Gore had his own documentary, he was a judge at a film festival in Nashville. He liked the winning film, The Real Dirt on Farmer John so much, he gave Farmer John a tour of his own farm at introduced the film in San Francisco.
All the screenings of the documentary were sold out last year at the San Francisco International Film Festival (where it won for best bay area doc), so I didn't see it until the Green Film Fest held as part of World Enviromental Day just over a year ago.
Al Gore sat just a few seats from me (the photo is pretty dark) as he was introduced by Carl Pope of the Sierra Club. Then Gore gave an intro to the film in the kind of style you see in his own film, with passion and humor.
I met Farmer John a couple of days briefly at a reception for the festival a few days earlier (and was able to talk to him more at a party later last year).
If you aren't able to see it on PBS or want to show the full version to people you know (the tv version is shorter), you can sign up to be notified when it is released on Farmer John's site (he also has written some books).
He was Community Supported Agriculture near you and subscribe to support local farmers.
And educate yourself on farm issues. The farm bill will be up for reauthorization next year. Christopher Cook's Diet for a Dead Planet which just came out in paperback is a good place to start (his site has lots of good resources).
And remember to check your local PBS listings, KQED here in San Francisco isn't showing it until next Tuesday (they are showing a financial show with Jonathan Pond instead).