Design is about solving problems. Some of these problems may be trivial, but it feels REALLY good to have a solution to them. Case in point: the rinser toothbrush. Instead of having to use a cup or your hand for water to rinse your mouth after brushing, the toothbrush has a built-in power fountain (or in New England terms, a bubbler). Brush your teeth, and while rinsing the brush, aim the water into the fountain, and voila! Bubbler action!