A site listing foreclosed and abandoned homes for squatting? Or perhaps the same for gardening? A house trading site so that you can trade houses with someone

A site listing foreclosed and abandoned homes for squatting? Or perhaps the same for gardening? A house trading site so that you can trade houses with someone where your and their job prospects are better? A better roommate matching site than any one I've seen so far? A kid-sitting exchange site? A more-local Ebay (not like Craig's List), more like the Ebay of old? Apprenticeships?