Space-filling curves can also be used for spatial indexing. Nick Johnson wrote a nice introduction to the technique on his blog: http://blog.notdot.net/2009/11/

Space-filling curves can also be used for spatial indexing. Nick Johnson wrote a nice introduction to the technique on his blog: http://blog.notdot.net/2009/11/Damn-Cool-Algorithms-Spatial-indexing-with-Quadtrees-and-Hilbert-Curves http://blog.notdot.net/2009/11/Damn-Cool-Algorithms-Spatial-...