mark:
I use a log - Reel-Times :-).
I used to do it by myself on paper then realized if I posted to R-T assiduously I'd have an on-line log so to speak.
Guess what - a few hundred others got the same idea and lo and behold we have a Maine -> R.I. log that gets better each year. Serioulsy - I often read old BBS's to verify what I think should be happening did in fact happen at the same time last year.
I also tend to have a pretty good memory of things that I care about :-)