Vertical Farming in NYC?
Amber waves of grain on the 15th floor? A "green sky" solution that means fewer carbon miles for food?
Vertical farms may not be the answer to all our problems, but they certainly are an intriguing concept.
I'm especially enamored by this proposed project, just a few miles from where I live:

You can read much more about vertical farming in this long entry at the TreeHugger blog, and also here on our blog.