Google Contacts
Free
Google Contacts is Googles contact management tool that is available in its free email service Gmail.
fruux
Freemium
fruux is a cross-platform synchronization service.
Memotoo
Commercial
Memotoo sync all your contacts from Gmail, Facebook, phone, Thunderbird, Outlook, etc in a single address book.
Compare FullContact with alternatives
Compare Google Contacts and FullContact and decide which is most suitable for you.
Compare Memotoo and FullContact and decide which is most suitable for you.