Nothing new here, no new castles found; but take a look at Castle DuPont's site, he's added some new pictures and you can see in very good detail the process of building a castle from CMU's. Currently, there are great pictures that show the CMU walls and waterproofing measures necessary to prevent water leaking into a partially earth-bermed building.
Also, I've been watching real estate trends to see what land might cost. After watching it climb rapidly in the last several years and now seeing it plunge almost as rapidly, it makes building your own house look more and more affordable. 1/2 - 1 acre north of where I live could easily cost $150K+, now there are multi -acre plots that cost less. I even found an 80+ acre lot for less than $100k, but with a price like that, it seems immediately suspect. Probably it is mostly swamp, is landlocked (needing to fight for an easement to get access), has no utilities nearby (an would cost a lot to get the utilities to), has environmental restrictions, high taxes, or any number of things that make the price not so nice. Still, if you wanted to go totally green and off the grid, it may not be such a bad deal.