Very cool app, cockpitvisit!

Once upon a time, I built a Google Earth mapping file of all Delta destinations from their key hubs in the U.S. It doesn't show the lines of the routes, show competing airlines or codeshares on those routes, nor automatically calculate the distance point-to-point (though I guess I could have it calculate that). It is by no means a replacement for what you have produced. It has its own place in an arsenal of FF tools.

But I have not kept my Delta file up to date nor expanded it to any other hubs or airlines. Is your data in a shareable format, and would you be willing to share it? (or parts of it?)