Cobook is a new Address Book application for Mac OS X that makes use of popular social networks such as Facebook, Twitter, LinkedIn and Google Voice to provide unparalleled functionality.
By using information stored in the cloud, it automatically adds and updates relevant information to your contacts.
You can set it up to sync Address Book.app and, if you’re an iCloud user, all your contacts will be available on your iOS devices. If you have lots of contacts, keeping your contacts up-to-date can be a daunting task to do manually – Cobook saves you time and effort. It’s a must have, and it’s completely free.