Maybe.

Of three or more views of a message:

http://article.gmane.org/gmane.comp.web.zope.plone.documentation/3393
http://thread.gmane.org/gmane.comp.web.zope.plone.documentation/3005/focus=3393
(I can't re-gain the third view, I'm endlessly lost in Gmane)

- it seems that only the first may be annotated, you might gain an annotated link such as this:
http://www.diigo.com/annotated/ae4addbb1d5bb04c9679de8f67f55c66

The combination of
Nabble embedded content + forced redirection to plone.org
- in particular, the way in which all topics and all messages within a forum are represented as myriad anchors to a single base URL - makes it impossible to annotate Plone support forums using tools/services such as Diigo.

It's anticipated that a future version of Diigo may be more flexible in such environments.

References:

http://groups.diigo.com/Diigo_HQ/forum/topic/nabble-2-embedded-content-incompatible-with-diigo-bookmarking-6643#6

http://n2.nabble.com/help/Answer.jtp?id=40

http://dev.plone.org/plone.org/ticket/1000

Guiding intentions:

a) any activity here should be wholly complementary to activity within/around plone.org

b) neither contradict nor undermine activities elsewhere.

With those as my guide: in the past I have drawn little attention to this group.

Now: it may be timely to make greater use of Diigo.

In any case:

1. anyone may apply to join this group

2. any group member may invite others to join.

The current moderation (of membership) is not an attempt at exclusivity. I wish to open the group more properly, if Plone communities are agreeable.

Key point: I have tested Diigo fairly furiously, for a reasonable period, and I'm very satisfied with developer/community responses to requests and suggestions from users..