The Liberator project aims to make an "open source" compressed earth block machine that can turn out 3-5 blocks per minute for a total cost of $1,000-$1,350. That's enough blocks to build a new house every day, turning dirt into shelter. The project page does a good job of making the case for the efficiency of compressed earth blocks, challenging some of the conventional wisdom on the subject.
Link (via Beyond the Beyond)
This page is an introduction to the collaborative development of a high performance Compressed Earth Block (CEB) press, The Liberator. We aim to provide a low-cost, ecological, ergonomical, and economically-significant press. The design process and final plans will be "Open Source"-- part of the public domain, with free access to anyone. The press is designed through voluntary efforts. Funding for parts, labor, testing, and development are procured via donations from interested parties (ie. builders, buyers, producers of CEB presses; community developers; general supporters of our work). At the same time, we are developing an open source enterprise, according to the principles of neocommercialization If you are interested in helping the development process in any way, please feel free to contact us.
(Image: Cebhomes.jpg, by Dan Powell, from Wikimedia Commons)