When working in groups, we often conduct face-to-face meetings to accelerate the exchange of ideas or opinions, or to complete a cooperative task. Collaboration, a natural and efficient approach to problem solving, has been one of the most challenging topics in HCI studies. We are conducting research to facilitate face-to-face collaboration during group meetings or discussions. Collaborative table displays are designed to enhance functions of ordinary meeting tables to support small-group collaborative activities and have lately considerable attention. We have proposed several types of display tables for cooperative interactions. Examples are