Google Maps - Determining Distances

Found a neat little feature in Google Maps today that lets you easily measure distances on a map.

When on a map, right click and one of the menu choices should be "Measure Distance".

You can follow the prompts, but basically everywhere you click on a map is a drop point and it gives you the total distance traveled from the first point.  It is really easy to use and gives you an accurate reading.
As you continue to click points, it gives you the total distance from your starting point.

How can you use this at a school? I'm sure once you think on it you can come up with many ways to use this tool (much more than I possibly could list).  

One thing that quickly came to my mind is to use it for field trips or races (fun runs) where you will need to know how far you will be going. Below I mapped out a course on campus for the fun of it.

I also did a quick route of how far of a distance Hawaiian paddlers would have to had to travel to go from Waianae on Oahu to Lahaina on Maui, with a stop at Kaunakakai on Molokai.

This neat feature is something that I think could be useful for history projects by students.
What do you think?