Confession time - I'm not so good with a knife. I've managed to avoid serious injury so far, thank goodness, but I suspect my time is coming. I'm also quite slow - that's where this gadget comes into play: It's pretty much like this Vidalia Chop Wizard found on Amazon.com.
It has two blade inserts (the green piece), one with large holes and one with smaller holes. It also comes with a little comb sort of thing that you use to comb junk out of the squares on the top piece that push food through the holes.
Clean-up is easy in the dishwasher - I have to say I haven't tried handwashing it. If I use it to chop onions, I rinse the blade as the tiny pieces of onion can get stuck on there pretty well. I also rinse the top pusher part to make sure there is no debris left in there. Believe me, it's much easier to get out before it dries on.
So far, I've used it on onions, peppers, carrots, and potatoes with pretty good success. It doesn't work very well on peppers that have been frozen and thawed, though. When I chop peppers and carrots, I cut them into slices, about the thickness that I want, then chop the slices. I use the cubed potatoes to boil and make into mashed potatoes, grilled potatoes or fried potatoes. I've not yet posted it in my freezer cooking section, but I like to make up a gigantic pot of mashed potatoes and freeze them. This thing makes it go TONS faster!
For more kitchen tips, visit Tammy's Recipes.