Do not confuse a mandoline with a mandolin. I am not telling to go out and buy a musical instrument for your kitchen (though mood music would be a nice touch). A mandoline is a wonderful kitchen appliance that changed my life.
A mandoline is basically a fancy slicer.The mandoline slices in several widths and thicknesses. It also makes slices, waffle cuts and crinkle cuts with firm vegetables and fruits.
We use it to make french fries and to slice potatoes into discs for recipes like au gratin potatoes. I have also used it to slice carrots, zucchini, and cucumber. But, we mostly use it to make french fries. Do you think it is dumb to have an appliance that really only has one use? Do you own a toaster? Yah, that's what I thought.
You may be telling yourself, "well what is so great about a mandoline?". My attitude about cooking is the more short cuts you make on the mundane tasks, the more time you have to concentrate on the actual food! And the mandoline will "slice" your time in half.
Anyway, I know not everyone needs one of these, but I am sure glad we have one!