Instead of conventional interactive device such as mouse and keyboard, developing new interaction technology and its application systems, contents and service model To prepare 'Disappearing Computer Age' as future communication technology, users expect to use computer without being even conscious of using a computer system. To do that, evolution is needed from conventional interactive device oriented system such as mouse and keyboard to user oriented intelligent interface. Gesture based interaction using infrared and camera in transparent interactive wall is presented. Laser pointer interaction technology is also presented for multi user interaction at a distance. User Interface : improving the technology that allows users to effectively perceive and express information