Great article.  I've used this type of bitmasking at match.com to the code the user profiles that are used in very fast matching to potential love mates.  It is still working today after 5 years and uses very littly space and computer time in search schemes to return up to 500 possibilities in less than a few seconds from a growing profile database.

Can't wait for the follow-on segments.

Don Bishop, SR DBA Consultant