Wow, everyone's so nice down here in the links section -- hobbit houses, reptile genitalia, no vampires...
That's a very cool abode, zenden. I know someone who's worked on several alternatively constructed dwellings, but it's difficult to do one as eco-friendly as that.
I noticed they used bales of straw as insulation. There are methods of building the entire basic structure out of straw bales. Basically you build like you're using giant legos and then spray gunite (sprayable concrete) over it all. When the gunite weathers it ends up covered with the local strains of lichens and moss and eventually, your house melts into the surrounding terrain. They're hurricane and tornado proof, and (it's claimed) earthquake resistant as well.
I'm not sure if the one below used the straw bale technique, but the "rocks" around the entrance were made from sprayed concrete.
There's a lot of information available about building alternative structures like this, for example:
http://www.daviddarling.info/encycloped … ction.html
...however you can't do it just anywhere. There are many localities where the building code people can't grok much beyond standard construction techniques.
Of course they're all modeled on Hobbiton. I'm think this is Samwise's house:
It would be interesting to discover how the hobbits kept their roofs from leaking. :>)