Here's an idea: transform a large, empty retail space into a place that grows organic herbs and vegetables. Called "big green boxes," these could potentially provide year-round produce for local residents, restaurants, and institutional cafeterias. They are described as containing fish tanks from which the water circulates out to the growing areas and then back to the tanks (after being filtered). The fish thus fertilize the crops.
Kind of an interesting idea. But if it didn't work out, it might be difficult to transform the green box back into retail space. On the other hand, if it's probably not going to be purchased for retail use any time soon and might even be torn down, an old store as a place to grow increasingly popular organic produce might be a good idea.