You know you've used it, but does it work? Yesterday in The New York Times, Harold McGee wrote an article on whether we can actually trust food that has been on the floor for less than five seconds. According to him, there is truth behind the notion that the longer food is on a surface the more bacteria it picks up. However, very small numbers of some microbes can still make us sick. Hence, McGee gives us the updated rule: "If you drop a piece of food, pick it up quickly, take five seconds to recall that just a few bacteria can make you sick, then take a few more to think about where you dropped it and whether or not it’s worth eating." Sounds reasonable to me.