Just had someone show me this web page. Ever wonder how far you run?
http://usatf.org/routes/map/ from the usa track and field organization lets you bring up a map of where you're running and plot it out. It will tell you the mileage and slope of the terrain. Then you can bring up a google earth image to check out what it will look like visually.
Here's the how to:
1. go to above web page
2. click on "draw map" on the left side of page
3. click on the map for your starting point
4. click on each turn point. A line will connect the dots. It will also give
you 1 mile markers along the route.
5. When done, click on satellite image on upper right corner.