Notify Me on Change
The CMFNotification product looks good, but this functionality should be a core feature of plone for any content (pages, folders, comments...). I'd like my users to be able to manage their subscriptions to content items in the site. Notify me by pushing out a twitter message, or emailing me.
This is already core functionality in Plone 3. Look at content rules. There's only a little portlet or similar missing