Every one of us is made up of more than 37 trillion tiny cells. Careful analysis reveals that these cells--small worlds within us--are not so different from the world around us. Every cell has a natural barrier, a postal system for importing and exporting essential goods, power plants, street cleaners, highways, libraries, criminals, a police force, construction workers, and much more. This class will connect the world around us to the one within us as we explore concepts in cell biology in fun and unusual ways. This class is also meant to provide students with the skills that will allow them to on their own make use of real-world models to better understand scientific concepts.