Slightly different scenario, but I needed to allow users to create posts with maps and link them to other MP Google Maps maps. The solution I came up with was to use two maps plugins – Simple Locator, which allows users to add a site specific map to their post, and WP Google Maps. Simple Locator sets two lat and long fields which a custom function I wrote picks up when the post is saved and sets markers on the WP Google Maps map.
I guess the key question is how do you intend to get the map into the users wall? Would it be an activity update that included a map or some other way?
