Hierarchical Trees

[Fran]

This looks cool:

http://code.tabo.pe/django-treebeard/src/

Single API to access 3 different models of hierarchical trees.

I'm inspired to move my simple 'Adjacency List' model to one more
suitable for Reads.
I've seen a Web2Py implementation of modified preorder traversal:
http://www.web2pyslices.com/main/slices/take_slice/27

Anyone have implementations for Nested Sets or Materialized Path?

F