From rdiez's Personal Wiki
The InviteContacts extension adds a series of new special pages for inviting your friends to ShoutWiki by sending email links to them. This feature is not active per default on new wikis, but you can request for it to be enabled on your wiki.
- Special:InviteEmail — allows for sending out invitation emails to your friends.
- Special:InviteContacts — allows for searching and importing of contacts from a GMail, Yahoo!, Hotmail or AOL email account.
- Special:InviteContactsCSV — allows for the importing of contacts from a .csv file.