Well after a quick look at ...
Published by Fabian Haas, Owner of Pixels in Screen
Well after a quick look at the website, let me add that photos with GIS can be used as proof & documentation on how things shape up in a location. Also, even without communication to an HG, the GPS tracking helps you not to get lost: with a track you just walking back. Ok thats a bit basic, but helps when night falls, street and road signes are messed up, so maps dont work anymore. For my scientific documentation I work a lot with GPS-Photo-combination Best Fabian