Thermal imagers are not only cool to play with, but also very useful.  Seek came out with a miniature thermal camera that works off your phone.  Not only is it cool, but the cost is about $200 which is cheaper than most units.  With this unit you just download an app onto your iPhone or Android and your pretty much ready to go.  The app allows you to perform various functions with this thermal imager such as picking a color mode, you can take temperature (even has a high, low setting).  Plus you can take pictures or videos.  The image quality isn’t the best we have seen, but for $200 it does a pretty good job.  Check out for more info.