When designing or implementing learning technologies, we are often faced with a number of competing demands including student interest, technical limitations, curricular goals, time constraints and the physical layout of our classrooms. Rapid advances in technologies such as social networking and augmented reality only exacerbate the issue. Despite this complexity, many designers continue to focus primarily upon the experience of a single user sitting in front of a single machine and, as a result, miss the many opportunities that these new technologies can afford us. To help move beyond the single screen, this talk will introduce some key elements of Activity Theory as a way of conceptualizing whole learning activities that include multiple students, the teacher, the technology, and a shared sense of purpose. I will briefly illustrate how Activity Theory might be used as a design heuristic, and then share a number of examples from my own work to illustrate the potential for thinking about entire activity systems instead of focusing exclusively on individual learners. In my examples, I will illustrate how the same theoretical approach helped me think about designing new simulation software to support kindergarteners in exploring complex systems concepts with an interactive whiteboard, and helping graduate students engage with theory using discussion forums and twitter.