As RegBlog reports, the White House recently announced the online
availability of extensive government datasets through Data.gov.

On December 8, 2009, the White House issued the Open Government Directive,
instructing Executive Departments to publish three high-value datasets online
within 45 days. As part of this initiative, the purpose of Data.gov is to
increase the ability of the public to easily find, download, and use datasets
that are generated and held by the Federal Government. Data.gov provides
descriptions of the Federal datasets (metadata), information about how to access
the datasets, and tools that leverage government datasets. The data catalogs
will continue to grow as datasets are added, so this is a website worth keeping
an eye on. Federal, Executive Branch data are included in the first version of
Data.gov.

Data.gov also includes a search engine, links to state and local data
sites
(available for only four states at the moment), and an interesting page
showing how many times each agency’s datasets have been downloaded. At this
point, the Environmental Protection Agency (EPA) has the lead.