The MapBag contains a small microcontroller, a GPS chipset, and a series of 8 vibration motors sewn into the bag. The microcontroller constantly evaluates the wearer's current heading and the location of magnetic North, or the relative location of a user-defined waypoint (such as home). The microcontroller informs the wearer of compass information through the vibration motors, basically allowing you to read a compass with your body.After using the MapBag for a few weeks, the slight pulses used to convey heading information have become second nature. Most importantly, I no longer find myself using street signs or depending on landmarks to discern my position in the city's grid.
And here's a video demonstrating the Drawing Machine: