YQL (Yahoo Query Language) works with arbitrary structured (XML or JSON) documents with repeating elements, such as a list of restaurants or search results. Different "known" collections of these items are presented as "tables" in the YQL syntax, and are notionally namespaced based on the service providing the data.
This geographic names data set provides a "mashup" of URLs for official city and county government web sites and city and county location data from the USGS Geographic Names Information System (GNIS). GNIS data includes incorporated places, census designated areas, unincorporated places, counties, and populated places.