Annotation of a site for developers, admins, and maintainers

I would like a way to take notes on pages that are only visible to certain roles. Adding a hidden field could do this but it's a lot of overhead, doesn't properly separate content from notes, and would apply only to content types.

For temporary content - "Hey we should do something else with this page, maybe such and such" - an input filter for hidden text would be perfect-- even something that really hides <!-- HTML style comments --> and displays them nicely.

For longer term notes, and notes about more complex pages and such, something stored outside content but associated with it would be a little better.

The Annotate module in the Drupal Pro Development books is one approach.

Old modules that don't quite do it:
http://drupal.org/project/admin_notes
http://drupal.org/project/hidden_content

The only active project with a close name (the one I would have picked) is
http://drupal.org/project/sitenotes

So maybe a combination of NancyDru's sitenotes and related_content would be exactly what I want.

Although my thoughts on something similar were to use http://drupal.org/project/advanced_help and http://drupal.org/project/helpinject

drupal notes on nodes
flag notes drupal

http://drupal.org/project/flag_note