Be aware that even the best (most expensive) infrared thermometer will give different readings of the same temperature, depending on the surface pointed at. For instance, given a copper pipe with hot water flowing thru it, if you point at a polished area of the pipe, and then at a tarnished area, you'll get readings that are quite different even though the water inside is at the same temperature. The relatively cheap one I have does that, and the instructions with it stated that it was only accurate to +/- 3 degrees F. Dan's thermometer says that accuracy is 2% of the reading, so if what you're measuring is at 100F, it could actually be 98F or 102F.
Buy a relatively cheap one and take the readings you get using it with a grain of salt. If you really need to know the temperature of something, use a contact type thermometer. Infrared thermometers have uses, like determining whether a cylinder of an engine is misfiring based on the difference in temperature between exhaust ports.
