Mobile apps are the natural evolution of the traditional audio tour, enabling visitors to self-guide around the galleries of museums. Rich content is at the heart of most museum experiences, but this pattern of engagement follows the traditional one-way communication model of museums, with the visitor a passive participant in their pursuit of understanding. In 2011 the High Museum of Art, working with Second Story Interactive Studios, set a goal of social engagement with their visitors, looking to create an app that was not only informative, but also made visitors a fundamental part of the experience. Leveraging natural user behavior and incorporating image recognition, the mobile app has been a huge success for the museum. In this paper, we present ArtClix as a case study for effective social engagement by the museum through novel uses of technology. We share the initial conceptual work in developing the application, the technical hurdles encountered along the way, and the resulting evaluation work across multiple exhibits.