I recently came across some clips for a documentary called Growing Cities: A Film about Urban Farming in America to be released in late 2012. The clip called "Farmer D's Young Farmer Advice" is especially inspirational. If you are trying to find ways to get started in urban agriculture, he gives a long list of great ideas!
If you've got some time, why don't you putter around their website. They even made several stops in Detroit including the Eastern Market, and Earthworks Urban Farm.