I just read two great accounts of survival and rescue, Frank (TA) accident review on Soaring Café and a book titled "Rescued", by Brian Brown available at Amazon.com. Frank told how he was able to get coordinates from his SPOT device and Brian told how rescuers "pinged" his cell number and got coordinates that weren't exact, but got the rescue chopper close enough to spot his flashing cell phone because he had installed a flasher app that flashed SOS. Brian and family had spent the night on a snow covered hill below the trees!
Both great reads,
JJ