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.
Cardhop - The Mac contacts app you'll want to use.
Drupe - Next generation contact manager and dialer.
Contalist - The contact app for professionals and small businesses
Simple Contacts - Contact lens prescriptions from home
The Contact Guru - Managing your contact list so you don't have to