Multiple Trees

As per the suggestion: http://brainstorm.ubuntu.com/idea/11493/
and this image:
http://img23.imageshack.us/img23/8027/mockupn.png

It could be possible to have another tabbed notebook containing multiple trees. So you could have a tree for Characters and so on.

I think this feature would be very troublesome to implement, and possibly not of much use. However, some people may prefer this arrangement.

There may also be a way to do this, instead of multiple trees, keep a tree, but use a tabbed notebook that will only show a subset tree. So if you clicked on the tab, it would redraw the tree but only from a node on. This seems more practical and feasible.