A free tutorial on creating Digital Elevation Models (DEMs) from Photosynth point clouds is now available online. The tutorial focus on using mostly free and Open Source software to create detailed georeferenced 3D models from low altitude aerial photographs that have been processed in Structure from Motion (SfM) software like that found in Photosynth and Bundler. Each step of the process is documented in text and illustrations. All of the datasets used and created during for the tutorual are provided for reference.
The tutorial is available here: palentier.blogspot.com