More common in California, New Mexico and Arizona, straw bale homes are inexpensive to build, green, sustainable, super insulated, sturdy, and highly fireproof. Apparently they are quake-proof as well(CNN Tech article).
Strawbale.com, blog, pictures, workshops, and information.
Straw Bale House Free Plans
Plans and Budget for Building a Small "Starter" Straw Bale Home (low cost to build - ultra energy efficient - no utility costs) ESTIMATED COST: under $10,000 including utilities. Also consider that these small home plans might make a nice in-law house or rental unit. A smaller simple version could make a cute playhouse, animal shelter(farm), or tool shed as well. The ideas are limitless and extremely affordable when using straw bale walls.
Straw Bale Home Construction
How Straw Bale Houses Work