What I really want to do is reduce the amount of data. For instance, I have a thousand points going in a line down Main Street. Because of the small errors in GPS, the points aren't mathematically in a line, but I want to save the data as a line segment, not as a thousand points. When the points make a left turn at 9th Street, I want to programatically detect that and have another line segment until the points turn or stop. I want my program to go through up to a million points and plot as few line segments on the map as possible.