I want to be able to file documents in one place, but tag them for action.

I've been meaning to find which one of these fits my workflow:

Quicksilver tag plugin [http://lifehacker.com/169971/metadata-as-a-filing-system]

TagBot [http://bigrobotsoftware.com/]

Punakea [http://www.nudgenudge.eu/punakea]

They all use Spotlight metadata to accomplish the tagging, Punakea seems the most modal, which I like less.