The Degree Confluence Project is busy photographing the planet one map grid at a time. The project wants to gather photos at every intersection of integer latitude and longitude degree lines in the world.
The site doesn't use the Google Map's API, although there is a Google My Map of the last 35 photographs added to the map.The project reminds me a lot of Geograph which is a similar project attempting to collect, publish and organise representative photographs for every square kilometre of Great Britain, Ireland, and the Isle of Man.
Geograph photos are licensed under a Creative Commons Licence. It would be great if The Degree Confluence Project agreed a similar license for the photographs submitted to the project. If it did then someone could create a mosaic of all the images and add it as an overlay on top of Google Maps, creating a map of the world consisting entirely of photographs.