A lot of kitchen gadgets have very limited use, and can be more trouble than they're worth for even that task. I started this thread to talk about those gadgets, for maybe better uses.
In another thread, someone suggested using an electric knife for cutting through frozen meatballs. Most people who have electric knives barely use them at all. I must admit that while, for food, they are of limited use (outside of cutting large roasts, I prefer a well-made sharp knife), they work GREAT for cutting through and shaping foam rubber to, for example, replacing fillings in old cushions.
But getting to food, I use a mandoline on a virtually weekly basis. It's easier to clean than a food processor, and I eat a LOT of salad (I use it mainly for celery, tomatoes, carrots, onions, peppers, and cucumbers). The problem with it is that the "guard" is, for most purposes, a joke, and the major danger of slicing your fingers with it if you're not using the guard. However, for about $20 extra, you can buy a cut-proof or cut resistant glove; in 3 years of using it, I've hit the blade with my fingers several times, but never got a scratch (note that I am NOT giving sources to avoid endorsing anything; you can easily look it up or ask at your local kitchen supply store).
So, what generally underused kitchen gadgets to you use?