This is what I have been looking into for the past few weeks: the straw bale home. It is now officially on my to-do list to build one of these within the next few years, so look out for updates. Its almost as easy as stacking legos or lincoln logs, so even with no building experience Ill be able to figure it out. Straw bales are much cheaper than traditional building materials, and by building your own home you can save enormously on labor costs. Plus, it insulates better, is more fire-proof, more earthquake-proof, much faster to build, eco-friendly, and (subjectively) better looking than traditional homes. Or at least much more awesome looking.
Check out this straw bale workshop: volunteers can pay a small fee to learn how to build a straw bale house by actually building one to near completion over the course of a week. For some what the heck is a straw-bale house 101.
Another material that anyone can build with is cob, an earthy mixture that is much more labor-intensive than building with straw bales, but can be used to make beautiful houses that look like sculptures. Cob costs almost literally nothing- you mix clay, sand, straw, water, and earth (similar to adobe), and stick it on top of other pieces of cob, and slowly it dries and you can sculpt a house. I want to use a mixture of straw bales and cob to make a unique extreme home that is off-grid, self-sustainable, and strangely shaped, like a fort straight out of a fairytale.
If you are interested in learning more about building cob houses, The Hand-Sculpted House is the best book to read. For Straw Bale info, try The Straw Bale House. For very thorough information about the background and building techniques of straw bale houses, read this free pdf.
Visit The Straw Bale Home for more information.