One morning last week we heard a strange cry outside our window. It turns out that it was a traveling knife-sharpener. So we gathered up the extremely dull IKEA knives in our apartment (when you're renting to strangers you don't exactly invest a lot of money in cutlery) and took them down to have them sharpened. He had his grinding wheel hooked up to the wheel of his bike, so he could turn it by pedaling. He also had a contained of water set up to drip onto the blade as he sharpened it, to flush away the filings.
Now our knives are so sharp that we live in constant fear of slicing off a finger.