Data dot gov

http://www.data.gov is a new website from the federal government meant to "increase public access to high value, machine readable datasets generated by the Executive Branch of the Federal Government" , which includes all federal agencies. There is a useful tutorial page to help you get started using the site. According to the site, a primary goal of Data.gov is to improve access to Federal data and expand creative use of those data beyond the walls of government by encouraging innovative ideas (e.g., web applications). Data.gov strives to make government more transparent and is committed to creating an unprecedented level of openness in Government. The openness derived from Data.gov will strengthen our Nation's democracy and promote efficiency and effectiveness in Government. Currently there are 592 datasets but more will be added. You can even suggest datasets that you would like to have added to the site.