Interesting use of LiDAR...

Here at Sagehen, researchers use airborne & ground-based LiDAR to create very high resolution digital maps of the landscape in order to image & model things like surface geology, snow-water equivalent (SWE), crown-bulk density & fluvial geomorphology.

Since the instruments are measuring both the first & last returns (basically light bounces), you can do some amazing things like strip off the vegetation layers to see the shape of the bare ground, & create topo maps at 1-meter resolution. By comparison, conventional topo maps are derived from 30-meter resolution data. With multiple scans of ground-based LiDAR, it's even possible to create maps at millimeter scale!

This music video by Radiohead is an unorthodox use of ground-based LiDAR arrays developed for the DARPA Grand Challenge by Velodyne.

See this link for a short "Making of" documentary, & to play with the LiDAR code yourself.