As anyone who has ever spilled coffee knows, liquids that contain suspended particles tend to leave ring-shaped stains when they dry. This ubiquitous phenomenon has been observed for thousands of years, but the physics behind it has only become clear over the past 20 years. In a related vein, while finishing a bowl of cereal, you may have noticed that the final few pieces tend to clump together on the surface of the milk. I will explain the physics underlying these, and other related effects. Further, though they may sound silly, these discoveries have many industrial applications, thus demonstrating value of understanding the basic physics of seemingly simple systems.