I was at Mini Makerfaire in Vancouver last weekend, and I came across a booth presenting a very interesting vest.  The Point Locus Wearable Tactile Pathfinder is a vest which reads GPS data, and vibrates on the wearer's shoulders to indicate the direction they should take along a path to a destination.  The vest should be used in tandem with a guide dog or some other tool to navigate obstacles, whenever the device is used by the blind.