As part of the PHP Developer's Network's effort to unify the sites that make it up, one of the things that we've been working on is a "unified search engine" so that you can go to the PHPDN website and be able to search all of the content for all of the sites at the same time, and get back hits based on relevance.
Well, I finally (thanks to Jason) got my end of the deal posted, and have an XML-based search for PHPDeveloper.org. If you'd like to give it a shot, check out this link: http://www.phpdeveloper.org/serviceNewsSearch.php?search_keywords=MySQL so see some of the results. It's a pretty standard RDF format, so it should be easy to parse it.
Ideally, all of the sites will have one of these eventually, and you'll be able to search the content from all of the PHPDN's Members all at once....