When you're grilling or cooking meat, it's important to monitor the temperature for several reasons. First of all, undercooked meat can harbor dangerous pathogens that cause food-borne illnesses. Secondly, you don't want to expect a medium-rare steak and end up with an overdone one. You can easily avoid both under- and overcooking when you use a cooking thermometer. A variety of thermometers for cooking exist. You can utilize a smoker thermometer or a BBQ thermometer, depending on what kind of cooking you're doing. Some thermometers actually feature displays that indicate whether you're at an appropriate temperature for smoking or BBQ. You can use a meat thermometer, which you actually insert into the food you're cooking, to check internal temperatures, or you can use a standard grill thermometer which monitors the temperature of your grill. Every kind of cooking thermometer has slightly different benefits, so make sure you choose one that fits your specific culinary needs. Be sure to grab a grill cover and grill grate too.
You can use an analog or a digital thermometer. Digital thermometers usually provide an accurate reading within seconds and feature LCD readouts that let you know the temps of your meat at a glance. Some can even compare the current temperature to the target temperature, designated by how well-done you want your meat, and feature an audible alert when the desired temperature is reached. Certain digital thermometers have a remote pager, so you can step away from the grill and still monitor what's happening out there.