If you're like me, early in my running career I was pretty anal about distances and times, and understandably so. When you first start out, the progress comes quickly as you progress from a non-runner to someone who can now run a half mile, a mile, your first 5K, then 5 miles, a half marathon, a full marathon...and, since you have landed on this page, eventually a real Ultra.
That's where this tool can come in very handy to plan out your routes: the Google Map Pedometer.
Knowing your distance and speed is pretty important, but eventually you may reach the point I am at, where I no longer keep a daily running log. Just seemed to be too much work.
But the Gmaps Pedometer still comes in mighty handy, as I just used it now to plot today's run as the bride drops me off on her way somewhere and I will run home.
Very likely there now is an app for a phone that does the same thing (probably better), but being old-school, I kinda like planning my routes on my desktop.