I posted some pictures of a tire-bale house that I built, under the Earthship category. This isn't the rammed-earth style earthship. This one uses tire bales. Our tire bale walls were set in place in 2 days. There is a lot of hype about straw-bale, but I think the tire bale approach is more sound. The bales are 5'x5'x2-1/2', and they weigh a ton each. They have between an R-45 and R-60 insulation factor. They are stacked with a skid steer. The mass of the finished structure is incredible, and this becomes thermal mass for heat and cooling retention. They are great for building a bermed structure, because they are so solid.
Before we built, we looked at a number of different types of green homes, thinking that we might buy one that is already completed. The straw-bale homes that we looked at, invariably had water issues, and mice. I'm sure this isn't always the case, and I don't mean to be negative, but your home is one of the most important decisions you'll make in your life. You owe it to yourself (and your family) to check out the alternatives.