I have developed something interesting for my graduate class in Computations Photography for the final project. As background, for the class we had an assignment in which we used the Microsoft Photosynth service to generate a 3D walk thru of an area by uploading several hundred photographs. On the back-end the Photosynth web service does feature extraction on all the photos and then related the photos in three dimensions to each other and the feature points. This generated a point cloud of related points between the photos.