Recently I went running out of town and could not get my GPS to work for me to know how far I ran. By using Google Maps, I later was able to map out the route and determine how far I actually ran instead of guessing the distance. The days of driving your car to determine that distance of the route is in the past. Further it does not work well where there are one way streets involved. Note a few weeks ago I did a post about Google Maps. I did not include this feature as it deserves its own space.
First you need to set up a Google account if you already do not have one. Once that is done, go to Google Maps. In the top right there is in red "New!". Select this option. Find the option "Distance Measurement Tool" and select "Enable". On the lower left of the map itself is an icon that looks like a small ruler. Once you have zoomed in on the map to your desired starting point click on this small ruler with your mouse. Then go to your starting point and click here with your mouse. Click at the first turn and all subsequent turns. If you make an error select the option on the left side to "Delete last point". While you are mapping your route the total distance to this point shows on the left side. When you are done, the distance I just mentioned is now the total distance of that run, walk, or bicycling that you have done.
I used this to measure the distance of a run I already did. You can of course it to plan a path for running, bicycling, walking, etc. It is a tool that can come in handy. However the next time you tell someone that it is a short walk to wherever you want to walk with them to, they can check if it really is a short walk later on.