The Internet Publicy Library 
http://www.ipl.org/div/news/
Searchable newspapers directory, with links organized by continent/country or in a title index.

Mediatico.Com
http://www.mediatico.com/en/
Searchable newspapers directory, with different languages version, includes Spanish, Deutsche, ltalian, French.

Nettizen.com
http://www.nettizen.com/newspaper/
Online, World Newspapers, Directory featuring detailed information about newspapers and franchise issues.

ThePaperboy.com
http://www.thepaperboy.com/
You can search the world newspaper since 1997.

refdesk.com
http://refdesk.com/paper.html
A comprehensive listing of world newspapers.