Papercrete

Now papercrete really is a good idea for recycling paper that goes to the landfill. I used to work at a recycling company, and many people don't know that the paper you carefully separate and put at the curb is often sent to the landfill with the other garbage, because its economical value is so low. It's not clean enough and/or the transportation costs make it not worth the trip to the paper mill.

Here and here are some good articles and also one from Mother Earth News. This would be feasible to build just with a couple of people. The only thing that is costly is the Portland Cement, but you don't use so much of it. Although I still am partial to stone.