I think I'm gonna try and actually make folders work properly in Tilemap Town's client, instead of the current situation where items are *not* displayed in a tree, and opening/closing folders actually just shows/hides items anywhere else in the list.
I'm going to call this a success, for now at least. I'm not entirely sure how I want this to look and I'm probably going to continue using Second Life as a reference, but unordered lists are good right now.