Map-enabled version of the Database activity latlong field (example at http://dbtest.conted.ox.ac.uk/moodlemaps/course/view.php?id=2)
Needs plugins local_map for map API, and datapreset_infomap_latlongmap for example of how to use the field with the database list view.
This is being built against Moodle 2.6+, but should work for at least 2.5.
If you're familiar with Git and can set up a test Moodle, the easiest way to try is to clone it from GitHub: https://github.com/Dave-B/moodle/tree/master-maps
This is a plugin version to help people unfamiliar with Git to try it; I'd like to get it included in core (MDL-42522).