I’m imagining a portable device that integrates a global-positioning system (GPS) receiver with a short range (say 25m) LIDAR (laser imaging detection and ranging) system that could be used to map the street-level topography of the earth–buildings, rooms, trees, streetsigns–as the user moves through it. I’m imagining a built-in-panoramic video camera that can be used to map textures onto all the surfaces. I’m imagining an internal hard-drive and/or cellular modem so that all this mapping information can be uploaded, sooner or later, to a central server that compiles location-mapping correlation data from multiple users to create an immersive 3D simulation of the real surface of the earth. I’m imagining stores and businesses and schools having sales, conducting meetings, and teaching classes at virtual locations inside the virtual earth at the same time they happen in the real earth, or even in lieu thereof. I’m imagining mappers competing to be the first to scan the inside of Kitum cave, or the top of Mt. Everest, or the basement of the Pentagon. I’m imagining that we’ll see it happen within 15 years. I’m imagining that the first people to make it work are going to be very, very rich.