2D video in 3D planar space.
PlanarVideo was a real-time video system that allowed for a live video stream to exist in a 3D / VRML environment.
Picture of PlanarVideo
PlanarVideo also existed as a real-time QTVR engine. Instead of planes, the images were arranged inside a 3D cylinder and streamed from a rotating camera. The user could then view a live 3D scene in VRML that updated on the fly.
Video of how the system worked and the resulting images: