To get the Longitude and Latitude on the globe from an address or a placemark, is what is called “geocoding”; the inverse, to get full address from Latitude and Longitude data is calling “reverse geocoding”.
Long time ago I developed a procedure to do both actions, using either GoogleMaps or BingMaps (VirtualEarth was its name). And it did the matter really well. But it has rained a lot since then. I don’t remember to use Google API keys (or at least, none I owned), and now, to perform this task, it should be necessary to have one.
Searching on the net came this clarifying post, from My Engineering World, on how to get one that shows how to do the job.
, and these other two (1 and 2) interesting posts are related to the subject.
As mentioned in post 2, it should be noted that using GAS (Google Apps) has the noticeable advantage of have not to deal with the API key, on the other hand, it forces to be bounded to Google Apps. Still no way to do heavy load work on the cloud.
No more on this subject until the mix of the posts…