Much like Detroit is reclaiming blighted areas for farming Cleveland is looking to experiment reclaiming the cellars of torn-down housing for underground farming.
http://www.cleveland.com/...
I find it a very intriguing idea. I haven't seen a reclaimed urban garden, but I have issues with pollution. (This is the same reason I won't eat in a side-walk cafe on the street). However, with underground air filtration, fueled by solar panels, this sounds like a really neat idea.