OpenInviter
OpenInviter is a free import contacts (addressbook) script from email providers like Mail2World…
SaaSiter Contacts Importer
Allow users to import contacts into their system.
AdiInviter Pro
The ultimate contacts importer and tell-a-friend system for your website.
CloudSponge
Companies from every industry use CloudSponge’s Contact Picker to get access to their users’ address books.