French company Meco Concept has taken this concept a step further with their Meco-Press (Note: website is in French). The portable press can churn out 30 LEGO-Style Blocks every hour. The bricks make rammed-earth houses simple to construct, and more flexible in their design. Building materials simply come from the job site, provided the soil on the job site is at least 20% clay. The bricks are quite strong, water resistant, but need help with insulation.
The Meco-Press is available for sale, or rent if you happen to live in France!