I saw this today and thought it was a very interesting construction technique: Grancrete.
I also saw a site on sandbag construction some time ago and I thought that it was also interesting
Either one could be used to construct a low cost shelter that could range from “bullet resistant” to “bullet proof”, depending on thickness. The grancrete could even be sprayed in successive layers to develop the desired thickness as it will adhere to itself unlike concrete.
I hope that you and yours have a wonderful Christmas and a happy and prosperous 2007! Regards, – Tim P.