In this paper, we explore ways to combine the video of a remote person with a shared tabletop display to best emulate face-to-face collaboration. Using a simple photo application we compare a variety of social and performance measures of collaboration of a standard non-spatial 2D interface with two approaches for adding spatial cues to videoconferencing: one based on simulated immersive 3D, the other based on video streams in a physically fixed arrangement around an interactive table. A face-to-face condition is included as a `gold-standard' control. As expected, social presence and task measures were superior in the face-toface condition, but there were also important differences between the 2D and spatial interfaces. In particular, the spatial interfaces positively influenced social presence and copresence measures in comparison to 2D, but the task measures favored the twodimensional interface. Categories and Subject Descriptors H.5.3 [Information Systems]: Information Interfac...