Here is a great Earthship video with links to many others;
http://www.youtube.com/watch?v=oBMiDKxqQKs"We need a billion of these, now!" Mike Reynolds
To me, eco homes must have as many of these characteristics as possible;
1)Low wood use, 2)a lot of thermal mass,3) use of indigenous materials,4) solar thermal gain, 5)solar power and/or wind power, 6)water catchment and/or recycling/minimal use,7) use of recycled materials,
super insulation and 9) interior year around gardens that grow food.
The Earthship is the "Holy Grail" of eco-homes because it can have all 9 characteristics. Others can be designed to have all nine also, like straw bale homes with trombe walls and interior gardens. An A frame could have up to 7 out of 9, and a dome maybe up to 6 out of 9 with difficulty.
7B next month, headin' toward destruction of epic proportions;
http://www.cosmosmith.com/human_population_crisis.htm