A nice heads-up from national access advocate Michael Ravnitzky:
The National Archives has, for the first time, released a database of the complete box holdings of the Federal Records Center. These are the records that are still owned by agencies and have not been acquired by the National Archives (though the National Archives does run the Federal Records Centers).
The database, which includes about 888,000 records, is in Microsoft Access format. It is about 155 MB but compacts to a 22 MB zip file that can be downloaded or e-mailed. This listing is truly the mother lode of federal records. You can download a copy until June 17 at this link.