Cartographica is a Geographic Information System (GIS) for your Mac with which you can explore and refine data, create beautiful maps, export information for the web using Google Maps and Google Earth (via our KML Export capabilities).
Merge data from several sources.

Get local data from your government in CSV Latitude and Longitude (or in your state plane, Cartographica has a deep understanding of Coordinate Reference Systems), add to that with satellite or topographical information using Web Map Services such as Terraserver or NASA's Blue Earth, bring in street information from US Census Bureau TIGER, and see them all together in one place.