Spent a couple of hours re-importing all the photos on this site into a dedicated iPhoto library and writing one or two AppleScripts to fix the titles and dates (Joe's stuff was invaluable in making those scripts a trivial endeavour, and iPhoto Buddy helps me keep these photos separate from my main library).
A few days with Keyword Assistant ought to be enough to re-classify a couple of thousand of them, I think... Then again, it's probably best to make it a couple of weeks.
While the scripts churned their way through the library, I played around a bit with Skim, and find it pretty damn useful.
It won't make as much of a change on my computer reading habits as Tofu (which I use to read long web pages in a more pleasing format), but the PDF annotation features are very straightforward to use (seemingly more practical than Adobe's), and the search function (which draws a red ellipse around matches on a page) is very effective.
iGTD also deserved a whirl (and seems pretty efficient), but I didn't spend much time fooling around - GTD is very mail-centric as far as I'm concerned, and my current approach is working fine for me.
Still, it might be useful to other GTD junkies out there, so give it a whirl (mind the yellow icons, though).