Hey all,
There are some very good ideas about for constructing very inexpensive shelters using bags and the dirt beneath your feet. The dome is one of the most structurally sound designs known to man. They can be dug in a fair ways and then covered over with dirt/grass etc.
http://www.networkearth.org/naturalbuilding/honey.html
http://www.networkearth.org/naturalb...earthbags.html
http://www.calearth.org/EmergencyShelter/eshelter.html