I found this video about Michael Reynold's Earthship project on the blog One Man Gathers What Another Man Spills, today.
The above image is the start of a house they built in France. They use old tires for the exterior walls--they are packed with dirt-- and old sheet metal from appliances and glass bottles and aluminum cans to build houses that are completely off-grid and sustainable. How cool would it be to own to one?!