Give Knives a Quick Bite

Well, here I am finally getting around to signing up, since I finally thought of a brief little techneak.
If you have a kitchen knife that just skids off the tomato you are peeling, you can give it a rough sharpening on the bottom of a mug. Turn over your mug, make sure it has an unglazed ring around the bottom. Drag the edge of your knife across that at a ~30 degree angle a few times. This should give you a rougher and sharper edge.
Sharp knifes are less likely to hurt you than blunt ones, but still, don't blame me if this Techneak helps you draw blood :-)