I was using Theodolite, a surveyor type app for the iPhone, to record "Benchmark Recoveries". Now applying it to documenting my headstone recoveries. I also supplement the headstone picture with two or three orientations photos. Theodolite imports the GPS, time and date and inclinometer data and overlays the photo just like a "heads up display". High tech meets the headstone. Generations down the road will be able to relocate the headstone without the caretakers help.