A utility for analyzing .pdf documents to extract older changes to the text and view previous editions (good for un-redaction?) as well as scrubbing the document history so that no one else can do the same thing to your docs.
Cryptome's page of TEMPEST documents, most of which are declassified NSA docs though there are also mirrors of TEMPEST info from the private sector. Also has a very interesting discussion of how STU-III phones can be accidentally compromised by stray RF. Oops.