Andy Rawson built an open hardware Thermal Imaging Device for use with Smart Phones (the code and details will be posted soon I am assuming). We have seen the commercial version of these Thermal Imaging Cameras used on home renovation shows to pinpoint insulation issues. As Andy mentions these cameras are much more than the average home owner could afford to spend to learn where his house is lacking insulation. For $150 I can see many home owners purchasing one to see where their insulation could be improved.