That thermal flashlight thing gave me a cool idea.
I was at the NAB show last week, and there was a company showing their thermal imager. $24K, and it shot 1024x768 video between 8 and 14 microns. Its output was in 256 levels of gray; I watched my Quark Mini heat up using it.
My idea: hook up one of these to an LED-based pico projector, and align it to the IR camera viewing angle so that the projector illuminates the camera's field of view. Presto -- a realtime heat scanner that directly projects the heat output of a surface right back onto that surface. You'd be able to directly "see" a hot water pipe right on the wall or under the floor. Hot objects get lit brightly (or in red if you run the video through a processor first), cool ones don't.
The artistic potential would be huge too.
LOL
You don't need a projector light to see hidden hot water pipes, etc, if you have an infrared camera. The heat is supplied by your target. For example, if I want to see a break in a radiant floor system, I can turn on the radiant heating system, so that hot water starts to flow through the pipes under the slab/floor...and I will see a picture of the heat coming up through the floor...it will look like the water in the pipes...and/or like the hot water leaking out and pooling under the floor.
You can set most FLIR, etc, cameras to display the temperature as a color...any color you want. I like B&W myself....and might make hotter temps show as whiter/lighter, and colder temp stuff look darker, etc....but I could assign say a spectrum orientation, to do the same thing.