Sadly, it's a story of one mistake, one death and one great technology. James Kim, a C|Net editor, with a car abandoned on a road in a remote Oregon forest, left his wife and two daughters on Saturday to seek for help, which he never found. That was the mistake – never leave the car.
The wife and children were found in the car on Monday afternoon, his body was found on Wednesday after Thanksgiving 2006. Aparently, the cellular phone provided a trajectory for the rescuers to find the car and the family. It appears that the family cell phone was in range of the tower long enough to register that the Kims had a text message waiting.
The wireless engineers of the operator were able to detect the call detail record and used that to focus the search effort, which led to the rescue. Here's the C|net story.