The thesis explores how interactive technologies and digital media can be used as transformative mediators and tools. They have the potential to strengthen and enrich the experience of different transformations that are discussed as being important for practices of creativity and learning, where the engagement and relationship to processes of change is fundamental. The flexibility of digital media and forms for tangible interaction constitutes major elements in the design experiments described in the thesis. Material artefacts and physical space play a central role in how people make sense of the world. Looking closely at practices where creativity, learning and communication are important for collaborative work it becomes clear that this insight implies that the concepts of objects and space carry quite a portion of multiplicity. They are used differently and with different intentions, they are understood differently from different perspectives and the look and feel of them appears differently even if they can be described as “one” thing or “one” space. Dealing with these heterogeneities challenges the way we use objects and spaces. It becomes a matter of connecting the multiplicities and how we configure them in relation each other. The research discusses how the discipline of interaction design can support dealing with multiplicity, configuring and mixing of objects and spaces. They are not only used or inhabited; they are performed and enacted. In exploring these issues the thesis discusses the development and experiments with a couple of design prototypes that rests upon basically the same technology, which is a combination of technologies for tracking and/or tagging. Studies and experiments have been performed in three different domains; design work, patient learning while undergoing lengthy rehabilitation and artistic work and performances. The diversity of studied domains provides a way of talking about design that focus on use and users’ appropriation of technology rather than reflecting the technology itself. From a methodological perspective issues of participatory design have been foundational to the research. Some design consequences refers to how we can not only regard interactive artefacts as bundles of functionality. We must also look into issues of giving form to them as material things and the thesis especially reflect how we can override a distinction of things being either material or virtual. Another consequence is how digital technologies often does not replace “analogue” media and material things, but instead are used in parallel and must find a place in an already existing ecology of artefacts, devices and services. In the thesis there is a strong focus on how human action is co-shaped together with artefacts and technology as we perform specific tasks or simply go on about our living and making sense of the world.