Try the Updated Science.gov

Science.gov 5.0 includes a single-interface access science and technology information from 17 separate federal science organizations and searches:

Also, for those interesting in unlocking more government data and information, get your opinions submitted to Show Us the Data by March 9, 2009. The project will result in a report that will recommend documents and data that the federal government should make more freely available to the public in usable formats.