ContactRescue - Magically get your address book up-to-date and accurate
MyLines - All information and contacts on one page
Cardhop - The Mac contacts app you'll want to use.
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts
Clearbit Connect - Clearbit Connect is a free extension that surfaces actionable information on the people who email you.
Wall Of Me - Wall of me: all your favorite socials in a single place.