I have made a k-NN search algorithm in matlab, and I want to implement it using a GIS data-set. A Google search didn't yield any good test data-sets. At this point, I have created a data-set by taking some random points, scattering them on 2-d space, and applying k-NN search to them, given a query location. This all works fine. Can this be used as a synthetic GIS data-set? Doe anyone know of any other data-set to work with k-NN search?