Google Drive - Access and sync your files anywhere
SaaSiter Contacts Importer - Allow users to import contacts into their system.
ShareFile - Secure file sharing and sync
AdiInviter Pro - The ultimate contacts importer and tell-a-friend system for your website.
Dropbox - Online Sync and File Sharing
CloudSponge - Companies from every industry use CloudSponge’s Contact Picker to get access to their users’ address books.