After spending a couple of hours shuffling old backup CDs around and marvelling at the foresight I had back in 1998 to use tar as a backup strategy on Windows (it has gross limitations, but forced me to make sure I was backing up the right stuff and with legible, easy to remember pathnames), I'm beginning to agree with the Knowledge Management pundits that we need something like the Rememberance Agent not only to help us manage the enormous amount of digital information we deal with every day, but to help us keep track of what we did in the past.
Projects like the Ximian Dashboard (shown above) might provide a partial answer to this (sadly, there are no Mac OS X or Windows equivalents that I know of) in the future, but for now at least my e-mail has been taken care of - with added benefits.
I've been running Zoë (a Java-based all-in-one mail aggregator, indexer and whatnot) for almost two weeks now on one of my boxes, which now holds a replica of 30,146 mail messages (around 4 year's worth of heavily sanitized archives, with another two years going in as soon as I extract them from Outlook data files), inside which Zoë has identified no less than 4,390 documents, 4,877 names, 2,203 organizations and 26,635 urls, all available for searching.
Using nothing more than a browser, I can now find virtually any document I sent or received via e-mail in seconds, which compared with the several minutes I spent watching Outlook grind through last year's archive is a significant improvement (to its credit, even though both Mozilla and Mail.app outperformed Outlook by an order of magnitude when searching inside my IMAP server, it is still faster against local files of roughly the same size).
Zoë is not without its flaws (it still has the odd bug and will not display even basic, "safe" formatting for HTML messages), but coughed up a nearly final version of the document I was looking for in my CDs in around a hundredth of the time it would take for me to find it by shuffling coasters, and that has got to be a good thing (it took me all of two minutes to find the CD with the final revision once I knew the draft date).