Drupal - taxonomy as menu block

The task is to create a block that contains a menu built automatically from a hierarchical taxonomy. Breadcrumb trail would be nice, but is optional. The menu module or blocks will do this, but as a mostly manual process of building a set of links into a hierarchy that looks and works like other menus in Drupal. This seems to be the quickest and easiest way for relatively static taxonomy or one where you want categories commingled with items from forums or aggregator or other areas of Drupal.

But my plan for this site is to create a taxonomy, and I would like to have the menu automatically built for this. There appears to be several candidates in the contributed modules list on the Drupal site.

  • Site map
  • Site menu - some nice looking features such as number of posts in each category, resulting block is not collapsible
  • Taxonomy context - includes breadcrumb and menu block
  • Taxonomy menu

As I think about this some more, I realize that one of these will certainly work, but the hard part is to design the taxonomy. Should it be free tags (del.icio.us) or hierarchical? Should multiples be allowed? Should it be required? When I started this post, I was thinking hierarchical since that is "normal" for menus and such. After thinking more about designing it and categorizing even a fairly small number of posts, I am wondering whether free tagging or folksonomy is a better approach. Sounds simpler in terms of adding and categorizing posts but not sure about how any kind of menus would work. They might need to change to recent, popular or something else since hierarchical is out and presumably there would quickly be too many for a simple list.