Evercontact - Your contacts always up to date and automatically with Evercontact.

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.

CONTACTBOX - CONTACTBOX combines the simplicity of an address book with effective functions of a CRM system.

SA Contacts Lite - SA Contacts Lite app comes up with features to help you in transferring all your contacts in your phone book between all your handheld devices without much of a stretch.

CRM-gx - Contact Management

Kontact - Kontact is the integrated Personal Information Manager of KDE.