Hi Everyone:
I have never done a PQ, but it looked a bit complicated for me. I was planning on spending some time working with it until a couple of days ago, when I downloaded the .kml add-on to Google Earth. If you haven't done this, do it now. It's awsome!!.
You can enter a start and end point like in MapQuest, and you will get turn-by-turn routing. The best part of all is that it will plot all the caches graphically in the area.
The only addition I would like to see is some kind of filter that will filter out the caches outside of whatever parameters you put in; i.e. route from A to B, showing only caches within a mile on either side of the route.
I don't know how difficult this is to program, but it sure would be cool.
If not, it's still pretty easy to pick out caches along the route as it now works.