The document discusses situated computing and proactive displays as an approach to ubiquitous computing focused on specific places. It outlines the evolution of proactive displays from early context-aware research prototypes to more advanced systems that can sense people's presence and activities in a space and respond through large visual displays. As an example, it presents CoffeeStrands, a proposed system using loyalty cards, phones and WiFi to create a place-based social network on displays in a cafe, allowing users to share content and connect more effectively in the shared physical space.