Recently I found a GREAT website.
So often I'll go for a run and can only estimate on how many miles I've run.
On this website you can track your route and get almost exactly how far you have gone. Also you can suggest routes to other runners. And see what routes others have done, and what they thought of them.
This website is especially helpful for windy routes, or routes that you can't drive the route to figure out the distance.
I LOVE IT and recommend it to all.