PinMeter is a little tool used to determine the distance of arbitrary points in Google Maps. It can be used for example, to measure the size of real estate, but it also works on larger scales as well: Would you like to know the distance from Alaska to Australia? Simply place a couple pins by tapping the screen.
Of course you are not limited to only two pins. If you want for example, to get an estimate of how far you walk in the woods is, try it out! It's a fun little app, and best of all..... It's free!