That's pretty cool, and, naturally, it looks like it was founded by some hippyish individuals not far from my home town of Eugene. Where else but Oregon or Northern California would people do something like that? :-) They do look like a pretty good option for a cabin for some land in the mountains. I wonder how well they do being left alone for most of the year.
My girlfriend's sister lived in one for almost 2 years in Southern Oregon. Held up just fine, no leaks, and it was around ten years old when she moved into it. She mud plastered the walls and painted using some natural pigmented paint she made, kinda cool. Compost toilet was a little walk down a trail. Southern Oregon doesn't get a ton of rain, so it's not that bad having one outside the house.