I’m not convinced this is the best way to do this as it doesn’t really allow the level of Google Maps interactivity I wanted (multiple simultaneous editing) but it is a possible first step.

If you launch Google Earth and choose “Network Link” from the Add menu and type in the URL:

http://rampancy.net/sites/rampancy.net/files/mombassa_odst.kml

You’ll get a blacked out Earth with a New Mombassa scan on it with a single (fake) skull placemarker I put on it.

This KML can’t be viewed in Google Maps, since Google Maps uses an entirely different method for displaying image overlays, but I might eventually be able to get that to work.

Anyway, if people were interested, they could load that KML, add placemarkers for stuff they’ve found, save them as KML files, mail them to me, and then I’d add them to the network layer.

As long as I keep the Earth coordinates of the image overlay the same, all the bookmarks should translate to any Google Maps version I might be able to create later.

The one thing I’m not sure of right now is scale— I don’t want to start collecting placemarks for the network layer until I can size the map properly. Is there anyone who can give me an idea of what the scale of the map should be, based on an in-game observation?

(I can’t do it myself, as I still don’t have the game yet).

UPDATE: I've repositioned the ODST map actually onto Mombasa in Kenya, on top of a likely-looking intersection that (mostly) fit was was in the map. I've scaled it so that the widths of the city streets match. That makes the whole map only a third of a kilometer wide, though, so I'm betting that scale is wrong.

Next steps would involve getting a higher resolution image and possibly converting it to a polygon to make it viewable in Google Maps as well as Google Earth.