Twitter Apps

The following WebApps can send updates to your Twitter account when new content is posted:

ListApp

ListApp

The mailing list manager can update your Twitter account whenever you send a newsletter. The tweet would include a link to an archived copy of the newsletter.
DiscussionApp

DiscussionApp

Your message board can send tweets with links to the latest messages.
CalendarApp icon

CalendarApp

Your calendar can send tweets whenever a new event is posted.