Dryad users can receive notifications of new content through the normal DSpace mechanisms, or via Twitter.
All newly archived items in Dryad are posted to the Twitter feed *datadryadnew*. This feed receives notifications via the service twitterfeed.com. Unfortunately, no one remembers the name of our account at twitterfeed, so it's currently black magic. If it fails, though, we have an alternate account ready to go at twitterfeed, with the username firstname.lastname@example.org and the same password as the twitter account.