SANS ISC has indexed NISTs hash database, http://isc.sans.org/diary.html?storyid=8236, and made it available online, http://isc.sans.org/tools/hashsearch.html.  They make a good connection between hash for known good software (sha1, md5 hash, or filename) and tracking malware and malware variations (MD5 only).

My co-worker is literally drooling over this because it is directly in his wheelhouse.

(edit: w00t!  This is my 200th post)

Another good resource, much appreciated.