Cardhop - The Mac contacts app you'll want to use.
Evercontact - Your contacts always up to date and automatically with Evercontact.
The Contact Guru - Managing your contact list so you don't have to
CONTACTBOX - CONTACTBOX combines the simplicity of an address book with effective functions of a CRM system.
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.
Pobuca Connect - Connect with your contacts.