Interactive tables are becoming increasingly popular. In this chapter, we describe a collaborative tabletop environment that is designed for brainstorming meetings. After describing the user requirements, we demonstrate different possible solutions for both the display and the tracking implementation, and summarize related work. Finally, we conclude with a more detailed description of the Shared Design Space. Using a digital pen, participants can annotate not only virtual paper, but also real printouts. By integrating both forms of physical and digital paper, we combine virtual and real drawings, threedimensional models, and digital data in a single information space. We discuss the unique way that we have integrated these devices and how they can be used efficiently during a design process.