Earthen Oven

I found a great site for the construction of a cob/earthen oven. The image above is one of many from this site which has fairly detailed information: http://www.geocities.com/mosesrocket/index.html
As soon as the weather warms up a bit I hope to build one very similar to this with my sister. I think every family would benefit from having one in the backyard. One of these would have been very useful when we had the ice storm a few year back and lost electricity for 2 weeks (I cooked most things on our barbecue). You can cook bread, pizza (yum!) and almost anything you would cook in a regular oven. The way it works: You build a fire in the cavity and once very hot the fire is put out (and removed) -- the cob keeps the heat and cooks the food which is put in the oven after the coals are removed and then the door is closed to keep the heat in (door is not shown in the picture above).
There are so many variations of the cob oven but this is the design I like the most.
Here is a more elaborate cob oven
and another cob oven