Thanks to the UP Library Bulletin, I found out that the Index to Philippine Newspapers (IPN) is now available online.
More than 140,000 articles (1988-present) from the following newspapers have been indexed:
KabayanClicking on the links above will lead to the websites of newspapers that are freely available online. Not all these sites, however, have archives that are indexed by search engines.
Philippine Daily Inquirer
Considering that those with archives aren't complete and/or won't always be available, the IPN may be used as another way to look for Filipino newspaper articles. It's still not completely finished and the articles themselves are not provided, but hey, it's better than nothing =)