I guess you know what Octrees and Quadtrees are so wont go into too much detail on them here, but they are basically a great way to hold static (none moving) game objects in groups for the use of culling and the like. As stated this is great for game...
Filed under: Generic XNA, Source, Bounds, Collision Detection, XNA 1.0, XBox 360, XNA Refresh 1.0, XNA 2.0, Geographic Grid Registration, Octree, Quadtree