FYI and interest, there is an Internation Organization for the Solar Cooking, called Colar Cooking International, where you can find rich resources on Solar Cooking. Methods for the designs of the cookers, methods of using them etc can be found there. It can be found at http://solarcooking.org.
A directory of the Solar Cookers promoters can be found in : http://solarcooking.org/directory.asp. It lists the solar cooker promoters country by country. You can check the link to my blog as in