The "Low Impact Woodland Home".
This is a real home that a family built in Wales. Simon Dale is a photographer and artist who built this home for less than $5,000 and completed it in less than 4 months. I showed it to a friend who told me, "That's great... if you're a hobbit!" While I agree it does have a Tolkien-esque feel too it, it is an amazing example of alternative housing.
Check out the full website here: http://www.simondale.net/house/index.htm