It's the Apple Peeler Corer Slicer. I just finished up canning applesauce, cranberry applesauce, and apple butter and did it in a fraction of the time because of this little handy gadget.
Although it's uses are limited (often time to apples and potatoes), if you're a canner, this tool is for you. It peels, slices and cores your apples all at the same time. You just attach the tool to a table and push the apple onto the center bar. Then crank the handle and it does all the work for you. You can adjust the thickness of the slices as well with an additional attachment.
I love this thing. Although I only use it for a few things, it was definately worth the money. My mom and I have both used it for several years and it's still in excellent shape.