The USGS is testing ground-based LIDAR systems [right] for monitoring geomorphic changes at archeological sites in the Grand Canyon. The hope is to mitigate the detrimental impacts caused by repeated surveys that ironically are intended to preserve the sites.
USGS has published a new report that sounds pretty encouraging about the use of this technology.
Ref: Evaluation of Terrestrial LIDAR for Monitoring Geomorphic Change at Archeological Sites in Grand Canyon National Park, Arizona; USGS Open-file Report 1384