A set of Cornell University students have developed a prototype top hat with a GPS that navigates the wearer using 3D sound. The electronics is a bit cumbersome but we get the idea and like the concept of a non-visual means of telling the user which way to go. Sound waves are manipulated to make it appear that its coming from the direction you are supposed to be travelling in.
The following video gives a description of the electronics….we can see an Adafruit GPS board on top
A demonstration of the technology