I just think the idea that items need to be in boxes in boxes in boxes is really fundamental -- that's something tags can do as well, just as easily.
I mean, when you get down to it, what's the difference? I need to navigate to /home/boud/doc/rpg/current_campaigns/ysella_and_moyri/2nd_year/ to save a file called 03.txt because it's the 3rd write-up of the campaign where the players are using the Moyri and Ysella character sheets in our regular role-playing game which is something I write, not something I code (code goes in /home/boud/src -- with a similar hierarchy -- no wait, code I write goes into /home/boud/prj, src is for the source of other projects.)
That's just the same thing as tagging, when you get down to it.