The government of Victoria, Australia recently created a pilot project to allow visualization and mapping of data from the state government. This application requires Silverlight.
From the VisualPlace blog:
"The purpose of VisualPlace is to show the value of an interactive GIS-enabled service for the visualisation of location based government information."
Every ten years, the United States embarks on a census to count every person in the country. The 2010 census date of counting is only a couple of weeks away (April 1st, 2010) so there has been a lot of census talk in the media recently.
ESRI has two free and quasi-light weight programs for the download. One is an server application for the exploration and viewing of 2D and 3D programs, the other is a viewer application.