We are in the middle of building a table of locations (more than a thousand locations, actually) with distances between each location pair. The end result is a pivot table of all of our locations, with mileages noted (not unlike the mileage grids one might find in maps and atlases. We have an Excel macro that grabs the mileages from MapPoint right now. It's not very efficient (yet), but it's reasonably fast. When it's done we can post it here.