I am wondering how people deal with georeferencing for the purpose of
making atlases (i.e., to town or county centroid) vs determining coordinates
for more specific locations. If the data are there, both could be useful.
Do people let the users build their own atlas from whatever level of
specificity was georeferenced, or do some have more than one set of fields
for georeferencing to different levels?
georeferencing to build atlases vs display points
Atlas construction
I'm not sure exactly what it is you seek, but I'll make an attempt. Let me know if this isn't what you were thinking of.
Spatial data for administrative boundaries are generally available as shape files that can be used in Geographic Information Systems (GIS) such as Quantum GIS, DIVA-GIS, and ESRI's products. There is a very good source of data for the whole world in the Global Administrative Areas (GADM) databases. For the United States, these include state and county boundaries, but not towns. For some contries, GADM has 5 levels of administrative boundaries. For towns in the US you would have to go to other sources, such as the TIGER Census data (http://www.census.gov/geo/www/tiger/shp.html).
So, for data of this nature, it generally isn't necessary to construct a new data product, unless it is to do add something more than the original data include explicitly, such as centroids and extents. Were you thinking of generating such a derived product?