A few of us who live in the city of Chicago are trying to grow heirloom vegetables on our rooftops in cheap homemade earthboxes. It sounds more than a little preposterous to suggest that what we're doing is a real solution to the huge environmental problems we're facing, but it might be a tiny piece. We think they're a great way to build connections in a fragmented social/political landscape.
Not selling anything, I'm giving "it" away.
Here's the Flickr link, along side the pics is a little how-to guide with plenty of links.
http://www.flickr.com/photos/7458996@N06/sets/72157603652656573/