gCensus - an effort to make geographic (Census) data freely and easily accessible to the public. A cool application has been recently launched by a PhD candidate from Stanford University - gCensus. Using an intuitive web interface, users select from a limited selection of Census data (this will be updated with more data as the project evolves) and select variables to be mapped. When finished the resulting data is made available for viewing within Google Earth.
The project was conceived when the developer became frustrated with the cumbersome interface and process required to work directly with the Census data and supplied mapping interface.
How to use the app:
To get started, launch the gCensus web interface. Select the data source from which you want to map data in the left-hand pane by clicking on it. After that, just follow the built-in instructions in the right-hand pane to navigate through the application. In the final step, you'll see a link asking you to "Click here to download your map". When you click on the link, you should allow your browser to open the resulting file with Google Earth. If the browser does not recognize the file as a Google Earth file, then chances are that you need to download and install Google Earth from http://earth.google.com. Once that's done, try clicking the link again and opening the file in Google Earth.
The app is written in a variety of languages including Perl, PHP, PL/PgSQL, and JavaScript and will likely move to Open Source in the future.
A sample image showing Census data as seen in Google Earth environment (Source: gCensus)
Note: the project is still in development and the developer is interested in securing help in the form of development time, hardware, and hosting for more data.