Measuring in Google Earth!
The ruler tool in Google Earth is very useful when you are looking at a certain area and you want to get an idea of the distance. There is a checkbox that really never attracted my attention before. It is "Mouse Navigation". It is enabled by default. What is great is when you are looking at a specific area and you disable this, you won't be able to pan anymore. It will let you measure without worrying about moving your current view: