Steven Johnson in a Discover article (May 2003, p. 28) - Reality Bytes - Imagine if SimCity wasn't just a game [PDF]:
"In a true mirror world, data would be mapped onto recognizable shapes from real life. For instance, to find information on a local hospital, you would locate the building on a computerized map and click on it with an “inspector” tool. Within seconds, the big-picture data about the facility would come into focus: number of patients and doctors, annual budget, how many patients died in operating rooms last year, and more. If you were looking for more specific information- say you were considering giving birth at the hospital-you could zoom in to the obstetrics department, where you would see data on such subjects as successful births, premature babies, and stillborns. Information about how the hospital connects to the wider city-what Gelernter calls topsight could be had by zooming out."