I doubt that the term mug-rug has made it into the dictionary yet but I am confident that soon it will be used as commonly as placemat is now! After all that is really what it is..... just a smaller version.
These mats are perfect when you are having a cup of coffee with a muffin or cookie, or any time when a coaster is just a bit too small. And it's ideal for keeping on the corner of your office desk or in a drawer where it's always handy at coffee breaks or lunch time. Your co-workers will envy you! :)