Earthquakes are an all too real threat in Japan and other areas of the world. If you ever find yourself without a home due to such a natural disaster, it would be nice to have one of these cardboard homes to throw up in the back yard. The Octagon costs 150,000 Yen (about $1,400) and comes with a built-in door, flooring, and waterproof roof. The toilet not included (nor available for that matter). It takes about three hours to erect and requires nothing but some extra large origami skills and a lot of tape.
Take a look at some other disaster housing designs: