Too intimidated to start your own urban farm? Check out these guys and their farming initiatives. If they can do it in New York on rooftops, why can't you?
http://www.brooklyngrangefarm.com/
"Brooklyn Grange is a commercial organic farm located on New York City rooftops. We grow vegetables in the city and sell them to local people and businesses. The goal is to improve access to very good food, to connect city people more closely to farms and food production, and to make urban farming a viable enterprise and livelihood."
