What can you do with an infrared thermometer?
Infrared thermometers work very well when measuring the temperature of hot oil. For deep frying it's not a big deal, as standard probe thermometers work fine. But for shallow frying or sauteeing, the IR thermometer does an excellent job at providing the temperature of the oil. (Note that IR thermometers are not accurate when measuring the temperature of a dry steel pan, as the shininess makes the pan look much cooler than it is. IR thermometers work fine on dry cast iron pans, though!)

IR thermometers work rather poorly when measuring the temperature of hot water, however! Rather than measuring the temperature of the water surface, which is usually similar to the mass of the water due to convection, it measures the average temperature of the water vapor coming off the surface! In my experience, boiling water measures about 200 F with an IR thermometer.