This will be great project if you can build good and optimized address book software for Mobile software with reminder. If you want you can develop online application having latest features such as reminding using emails and sms.This project will sharpen your concept and develop your business sense.
Download SourceForge.net Source Code of PHP Address Book
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JContact is an online address book management application. It is web
based J2EE application build on JSF, Spring and Hibernate. The web2.0
framework Rich Faces makes the application more interactive.
Address book reloaded This is a PHP addressbook web application to store contact
details of employees/customers in utf8 format on an intranet or website;
features Google Maps, distributed management, PDF address books,
plugins, styles. DEMO: http://tab-2.sourceforge.net/
Online Address Book (OAB) is an open source PHP web application designed
for persistant, web-based storage of contact information. It provides a
flexible and convenient interface, and supports importing and exporting