Xobni - Xobni provides effortless email and address book management and search for Microsoft Outlook and BlackBerry. Put a face to every name. Lightning fast Outlook Search.
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
Live Inbox - Live Inbox is a Microsoft Outlook plugin that helps you organize your email and search your inbox.
Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.
X1 Search - X1's Lightning-Fast Search Software. Premium Alternative to Windows Desktop and Outlook Search.
FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts