OK, IE just fscked me out of my nice WU on this topic, so I'll sum up. At the database/code level, writeups and nodespheres should be freely associable: a writeup may be in n topics, and that topic may be in n topics. An example: Both a writeup under Ronald Regan and the nodesphere/topic "Ronald Regan" might belong in both "Actors" and "US Presidents". What about Michael Jordan? I think my flip top box should be in both "Everything:Arts:Industrial Design:Packaging" and "Everything:Vices:Tobbacco"

moreover, "cd .." doesn't make sense except in context; without knowing what path you were looking at, a topic should have no "real" parent. When looking at the Ronald Regan nodesphere, one might want all its paths listed at the top. What i'm trying to say is that this doesn't want to be a strict tree structure.

more as time permits