This item is very useful here in the Southwest of the United States, but may be less important in the Frozen North. There are many different types made from ceramic and plastic, but testers have found the insulated fabric type to be far more effective than any of the others. It's also easier to store when not in use. The photo specimen, which can hold tortillas up to 10 inches diameter, was purchased from www.latortillaoven.com, where many designs are available.
The fabric tortilla warmer (and some other kinds) can be filled with tortillas and heated in a microwave oven, but you are limited as to how many at a time, depending on the moisture content of the tortillas. If much steam is generated, they tend to come apart and stick to each other. For more details on warming tortillas, see below.
This warmer is just fine for Indian chapatis also. Here in Southern
California, whole wheat tortillas and commercial chapatis are pretty
much identical, and are made on the same equipment. Indian women here
don't have time to develop the traditional skill of rolling out perfectly
round chapatis by hand, so Indian markets sell tortilla presses for
that.
Microwave: Place a stack of 5 tortillas (not more) on a microwave plate and cover with a damp paper towel. Microwave in 30 second bursts until they are thoroughly warmed. Some recommend interleaving tortillas with paper towels so you can do a bigger stack.
Oven: Wrap a stack of 5 tortillas (not more, or there will be too much steam) in aluminum foil. Place in a 350°/175°C oven for about 15 minutes.
Stovetop: Heat an unoiled comal or tava very hot. Fry 20 to 30 seconds on a side. This method will get you a few browned spots. It works best with very fresh tortillas.
More on Kitchen Gear.