We're in the process of replacing some basement windows that have rotted around the edges because they were in contact with the earth. Of course, plenty of people replace perfectly good windows for other reasons, e.g., to replace them with more efficient ones, and they leave them out on the street. A special little truck comes and takes them, but anybody could take them.
We have a bunch of bricks in our backyard sort of lying around, that we're about to put on the Yahoo group, Hudson Valley Ecycle. And bricks wash up on the shores of the Hudson River all the time thanks to the old brickyards—aesthetically distressed by the tides! It's a public service to haul them away. A former next door neighbor of ours scored some large bluestone tiles to use on his patio, when he noticed that the town of Hurley was mysteriously yanking and trashing its historic sidewalks. And there are abundant sources of junk metal for the enterprising welder.
It strikes me that Ulster County is a good place to build your own house of found materials, if you're handy enough, have the time, and own a pick-up truck. What you don't find by driving around, I imagine you could find on Ecycle or elsewhere on the internet, or through Hudson Valley Materials Exchange, or some other way. How about an annual award for the most recycled+reclaimed house? It could be the sadder-but-wiser sibling of those fancy LEED competitions. I'm willing to bet that the lower carbon footprint is made by the scavenger.