Interactive tabletops and surfaces provide rich opportunities for data visualization and analysis, and consequently are used increasingly in such settings. In this article we discuss the potential benefits of using interactive surface platforms for visualization applications and present a research agenda of some of the most pressing research challenges in this space. The agenda emerged from discussions with researchers and practitioners in human-computer interaction, computer-supported collaborative work, and a wide variety of visualization fields at the DEXIS 2011 workshop on "Data Exploration for Interactive Surfaces