Frank Aragona has an interesting company by the name of Agricultural Innovations. They are using technology to promote permaculture and sustainable practices throughout the United States and Latin America.

I was really impressed with the block press pictured to the right. Two people can make an average of 300 blocks in a day using this machine, which works on hand power. It requires a mix of 90% dirt and 10% cement, although the earth should have some clay and other minerals with agglutinating properties.

I just finished listening to episode 49 of his podcast, and if you like this subject it might be something worth checking out. He's got a good speaking voice and I like his style. I give his podcast two thumbs up.