A post-dinner coding session turned into a sort of witch hunt as Safari, Mail.app and iTunes crashed in quick sequence. After Terminal crashed too, I started removing all sorts of extra services, input manager crud and twinkly little preference panes from my user profile. So far I'm not quite certain as to what caused this, but it is damned unnerving.
(A full hardware test done a couple of days a go revealed nothing, so I'm pretty sure it's not wobbly RAM or something like that.)
In much the same vein, I finally installed mt-daapd, since my current build of daapd crashes iTunes 4.7.1 for whatever reason. My current HOWTO stays, of course - for all I know, the iTunes crashes might not have anything to do with DAAP at all.
Guess it's time to order another cartload of books and get my mind off things.