Sharpen Your Knives on a Coffee Mug

So, I was recently reminded that you can sharpen knives on the bottom of a coffee mug. This is good since I've been complaining that my santoku knife is getting dull. Over the weekend I tried sharpening it by honing the blade on the unglazed portion of the bottom of a coffee mug. In the process, I managed to cut my finger. I stopped short of an optimal sharpening, but the difference was very noticeable.

Today my roommate cut his finger with the knife; a cut that probably would not have happened had it been duller. He cut himself in the same spot I did. Strange coincidence. Anyway, you should try coffee mugs for sharpeners. That way you won't have to buy a sharpener. Save money, save space in your house, save resources.