So, I'm intrigued by some technology called Indoor Atlas that basically takes the idea of global positioning and brings it indoors. Only, instead of using global positioning systems signals, the maps rely on the magnetic sensors on your phone.
“Each building, floor and corridor creates a distinct magnetic field disturbance that can be measured to identify a location and generate a map,” says Janne Haverinen, one of the researchers working on the technology. “When iPhone and Android phones arrived with built-in compasses, we realized that we could develop an innovative indoor navigation solution by applying our digital signal-processing expertise. Until now, it has been necessary to install Wi-Fi networks or other beacons inside buildings for location-based services. With our software, however, mobile apps can locate a mobile phone user in the building by utilizing nature’s infrastructure, the Earth’s magnetic field.”
So, basically, you could track someone down in a building through their smartphone. Or, to flip things around, you might use the technology to guide them to something you want them to look at.
Check out the video simulation below for more: