http://www.livescience.com/scienceoffiction/050909_quick_housing.htmlThe links within this article offer many ideas.
The biggest problem I see with any emergency housing is having it in the hands of the bureaucrats. If emergency shelters were part and parcel of money allocation from groups such as Red Cross, then maybe emergency housing would stand a chance of actually happening and not being shipped to other states, left to stand out of reach of the survivors or just plain having the needs of the survivors ignored. Any ideas/materials for emergency housing left in the hands of the government could stand the chance of never being used as intended.
Re: rammed earth/Eco-friendly green possibilities:
IMO, it has to be taken into consideration that the ground may be contaminated and not viable. This also goes for rammed earth and/or re-use of items at hand in the disaster zones.that have been in contact