I thought this was the damndest thing. A solar cell made from powdered donuts, tea, and vodka. No, this is not a joke.
Obviously not practical, but it does work. YouTube - A Delicious New Solar Cell Technology
Yeah, but if the materials can be made cheap and on crude equipment it doesn't matter so much. You'd have to do some pretty extensive practicality studies to see if it was worth it though. More a novelty than anything else. But it's nice to know some people think out of the box =)