The high tech wrist watches with GPS built in them, what is the GPS for?
http://www.rei.com/product/867476/garmin-tactix-gps-multifunction-watch (here's one example)
Is it used to help you find your way? As in, can you start running in the middle of Manhattan to nowhere and then use the watch to help you get back home?
Or is it solely used for stats, like tracking your speed?