I've been thinking for a while that I don't quite like directories, as organizing metadata. Too restrictive: you can only really choose one place, to find something you already have to know where to look (or search through everything), and if you choose long, comprehensible names, your unique set of metadata to find a file becomes very long.
Consider, by contrast, a service like Evernote.com (KPhotoAlbum also does tags well, and delicious.com for web pages). It has folders, yes, but what's better is that it lets you assign keywords to the note (really just arbitrary textual (or other) data). The note's topic is in essence the combination of all the keywords, so if you are interested in one of those keywords in the future, looking for the keyword (or some combination of keywords) would list all the notes with those keywords attached. I think the latter approach would produce a more usable, less frustrating filesystem than the former. Jason Catena
