Developer.com has posted the latest part in their series on using the Google Maps API. This time they focus on something a bit more complex - working with more than one point and creating complex routes between them.
This installment tackles another fascinating aspect you'll undoubtedly encounter when building location-based solutions, namely distance calculation. Whether you want to simply plot the distance separating two points on the map, or perform more complex operations involving measuring the total distance spanning a more complex route, understanding how to perform these sorts of calculations will prove invaluable time and again.
The tutorial gives you example screenshots and complete code to calculate the distance between two points and, based on plots of a few different points, how to determine the distance traveled. His example is of a running route around a park.