My brother, Abe, and his wife, Josie, built an amazing house down in Terlingua, Texas, basically out of mud and empty bottles. OK, that's oversimplifying it, but they built the dwelling with their own hands, mostly out of adobe, rocks they collected from their property, and other scrounged materials. It's a beautiful, self-sufficient abode that includes a rainwater catchment system, solar and wind power, and a groovy Tolkienesque fireplace. They've now moved to the state of Chihuahua in Mexico, and are working on another house while raising a new baby.
During it all, they've been chronicling their work and documenting their research, so that others can benefit from their mistakes (just a few) and hard-earned knowledge (lots and lots). For anyone considering a life off the grid, or just interested in what it takes, their Vela Creations website is a great resource, full of practical information and in-depth how-tos.