Google added a new measurement tool to the newer version of Google Maps. To use the measurement tool just right-click on a map and select "measure" then left-click on another location to measure the distance between the two locations. In the video below I demonstrate how that feature works along with a couple of other neat options.
Applications for Education
One of the best uses of the measurement tool in Google Maps is to have students complete activities like the Maths Maps activities developed by Tom Barrett.