Is there such a thing as shoe covers or shoe socks for bike shoes? I am wondering if I can buy some sort of shoe cover so that I can walk in my bike shoes without feeling so worried that I am scraping up the cleat on the bottom. I don't normally walk around on them, at all, but the other day I was riding and thought about taking in a light lunch before finishing the ride back and didn't dare to walk in to a restaurant in my cleats. Suggestions, please. :)