I keep my list of who taught, who attended, who's on what mailing list, etc., in a small SQLite database, because it proved to be simpler than grep/sort/diff when it came to answering questions like, "How many people who attended boot camps as learners have helped or taught at least once at an institution other than their own."  Plus, one day we'll have a real project management tool of some kind that I can slop this stuff into, and I'll be ready.  (Which I realize makes me sound a bit like the guy building a bunker in his back yard for when the aliens arrive...)