This is an interesting idea, but it seems like an awful lot of work on my part to go through and organize and tag every file.  While some of it could be automated (pulling ID3 tags out of MP3s), a lot of it seems to depend on me figuring out good names for everything I make.<p>The biggest problem is that I have to figure out which tags are going to be useful to me in the future and where to add them.  This is relatively easy for music (but even there can explode in complexity depending on how granular you want to be), but more difficult for things like photos or papers.<p>IMHO, fully general tagging systems never work because the complexity explodes as the number of potential tags increases.  You need to narrow the scope down to a specific domain so your tags can be limited to human scale.