If you're interested in geotagging, digital maps and related matters, here's a new article by several members of the Stanford Info Lab that you might want to take a look at.
Title: Assigning Textual Names to Sets of Geographic Coordinates
24 pages; PDF.
NameSet is a system that translates a set of geographic coordinates into a textual name based on the geographic regions where the coordinates occur. One possible application of NameSet is to concisely present the geographical scope of a set of geo-referenced observations to a human user. Another application is to generate text to depict a set of coordinates that appear on a web site -- text that could later be used for information retrieval applications. NameSet's computation is based on a simple algorithm, using off-the-shelf and web-based data sources. The system was proven effective in an application that automatically organizes and names sets of geo-referenced digital photographs.