Just a few comments around infared cameras. I was a diagnostic technician for a large manufacturing company. In that capacity I did vibration analysis of rotating equipment, infared thermography on electrical equipment and ultrasound on various equipment. These technologies are considered no-evasive and in most cases the equipment does not have to be shut down for inspection.
I do not use Infrared cameras in my Home Inspection business, because I am still building my business and cannot afford the cost of even the most inexpensive cameras.
I believe an infared camera would be a good tool, if you see a moisture stain and would like to determine if it is a past stain or a current problem. Another opportunity is the inspection of an electrical panel. Loose wires or other problems would show up during the investigation. With proper training roof inspections would also be another area of additional business. However, when I received the training, most roof inspections were conducted at night when the temperature cooled down and the moisture could be spotted.
I currently use my infared thermometer for investigating water spots and electrical panels.
I agree that as the price of these cameras come down, they will become another tool for the property inspector.
And yes I was taught that a good inspector only needs a piece of paper, pencil and a flashlight for doing inspections.