There's a new website sponsored by the federal government designed to facilitate access to a vast assortment of government-collected data. The index/archive is still relatively small, but it is expected to grow over the coming months and years. Take a look for yourself:
From the site"The purpose of Data.gov is to increase public access to high value, machine readable datasets generated by the Executive Branch of the Federal Government. Although the initial launch of Data.gov provides a limited portion of the rich variety of Federal datasets presently available, we invite you to actively participate in shaping the future of Data.gov by suggesting additional datasets and site enhancements to provide seamless access and use of your Federal data. Visit today with us, but come back often. With your help, Data.gov will continue to grow and change in the weeks, months, and years ahead."