There are two geolocation services I think would do a lot to help anthropologists: 1. Information about existing research which pertains to the current region, and 2. data on the presence of researchers currently in a particular location.
The second one already exists, in a way, in Google Latitude, which will tell you where your friends are at a given moment. But my idea would be to be able to see on a map the presence of any member of OAC on a map, so that we could better facilitate real-life collaboration between members of OAC.
The first one would be something like the feature in Google Books which shows you places mentioned in a book on a world map. Sure, one can research data by keyword, but this isn't very helpful when names have been changed to protect a community, and it often is difficult to identify research conducted on the East Coast of Taiwan, as opposed to other regions. Such a map could not be too accurate, for privacy and data-mining concerns, but it would be good to see all research conducted in a particular county, or other regional partition on a map.