Nearest Neighbor

A bunch of links on the nearest-neighbor problem, for higher dimensions:
http://www.mit.edu/~andoni/LSH/
http://www.cs.umd.edu/~mount/ANN/
http://www.cs.sunysb.edu/~algorith/implement/ranger/implement.shtml

And, for good measure a set of comparisons of optical flow algorithms:
http://vision.middlebury.edu/flow/eval/

I'll probably stick to the OpenCV defaults anyway, but its nice to know there are options. It would seem Bruhn et al. is the most accurate..