I think this is a great example of what pg wrote about in "The Power of the Marginal".

Link: http://www.paulgraham.com/marginal.html

I aslo like the quote from the article:

“There’s alternate ways of growing food,” he said. “I don’t want to push it down people’s throats, but if someone’s interested, I’d like to show them you can do this with cheap parts and a little bit of Yankee ingenuity.”