Using Google Maps you can collaborate on a map and add in details not on the original Google Map. We did this on another message board I'm on for a fishing Lake in NY by naming bays, islands etc. Many of these locations are now identified on the main Google map. It seems Google will pull data from these "personal" maps for use in the main map. That may be the best way to go.
I registered a domain that redirects to our "personal" map if you want to take a look:
blacklakenymap.info
