I came across announcements for 2 additional sessions at FOSS4G 2011, which is being held in Denver, CO Sept. 12 -16. The first is on using GRASS GIS to visualize LiDAR data, and the second will focus on the libPC and libLAS open source libraries. It certainly seems like there is a growing interest in open source LiDAR software. If you are using an open source software to work with LiDAR data perh