I made a fireless cooker at a Feb. 2011 workshop led by Dave Wall and Brita Butler-Wall. I moved soon after and it has been stored since, finished but unused.
FREE. If you'd like it, please let me know today (October 19, 2016) if at all possible.
This is a box with a tight-fitting lid, insulated with hay covered by canvas, into which you put a pot with a tight lid that you have heated up on the stove. The heat is trapped and the food keeps cooking without added energy/fuel.
I have the workshop handouts to go with it.