Tristan from Open Source Ecology sez, "This comprehensive, user friendly video shows you how to assembly the Liberator CEB Press; the worlds first open source, automated compressed earth brick making machine. Made from $4000 worth of parts, this machine sets a new standard in affordability, allowing users to build almost any type of brick structure out of dirt."
The OSE Wiki page has full instructions for building your own:
(Thanks, Tristan!)