Cobook, a smart address book that lives in your menu bar, is launching for free today in the Mac App Store. I've been testing a beta version of Cobook for a while now, and it has truly changed my day-to-day productivity workflow. Adding contacts is lightning fast, and searching for people is equally snappy because you can bring up Cobook with a system hotkey. In essence, Cobook is to Address Book what Fantastical is to iCal, but with one huge added detail: Cobook ties in to Facebook, Twitter, and LinkedIn to automatically pull in contact pictures, email addresses, birthdays, phone numbers, and websites. And unlike Fantastical, Cobook can operate as an app outside your menu bar, which is a nice feature.

Cobook also lets you non-destructively add tags to contacts like #BestFriends or #PeopleIHate so it's simpler to organize groups of people. There's the option to merge contacts, strip contacts of information (like a birthday), and do other batch editing you can't do in the Mac's Address Book. Other premium organizational features could come as paid add-ons for business users, the company said in a blog post today. While Cobook reads and edits contacts in the background through the Mac's Address Book database (which is less than perfect syncing with Google Contacts), founder Kaspars Dancis hinted that the company is working on a solution of its own that will be far more reliable syncing with Google. Good thing, too, because the Mac's default planning apps are sorely lacking in their compatibility with Google Contacts and Calendars. With Cobook and Fantastical, an entire contacts and planning solution can live in your menu bar, and can even be set as your default apps so Mail.app or Sparrow won't know the difference.