Long article on Cell phones in Yellowstone and Glacier

We were in the Smokies several years ago on one of the trails (don't recall the name right now) that is considered difficult. Girl in her twenties hiked to the top in flip flops and a cell phone to her ear most of the way (about a 40 minute hike). While on a wet, smooth, rock formation at the top of the trail, she slipped and hit her head. Phone went flying into a pool of water. There were about 20 others present, and they were able to call the Rangers and start assisting her back down. Doesn't prove a point either way as to a cell phone's importance; just an observation about something that seems all too common today.