Radio Tags Provide Guidance

This could also be easily used to embed stories and narratives.
From Technology Research News September 24, 2003:

University of Rochester researchers have found a new use for the radio frequency identification tags that manufacturers are aiming to use to track products like cartons of milk and sweaters. These radio ID tags contain small radio transponders that broadcast unique identification numbers. Radio receivers in retail stores and warehouses could monitor the tags in order to track inventories in real time. The Rochester team has reversed the standard setup by making the receivers mobile and the transponders fixed. The arrangement, dubbed Navigational Assistance for the Visually Impaired (NAVI), can provide location information for the visually impaired and for other kinds of navigational assistance applications like self-guided tours. The system includes a set of permanently mounted passive transponders and a reader/playback device carried by the user. Rather than tipping off an inventory system when a specific item is near, a transponder trips a particular CD track when a playback device comes within range. The system could be a low-cost alternative to global positioning system-based schemes for providing location-specific information and pedestrian navigational assistance. The system could eventually be used in self-guided tours of places like museums, and as a way to give people directions in complicated and confusing buildings like medical centers. The method could be used in commercial products in less than two years, according to the researchers.