<p>Is there a PHP class/library that would allow me to query an XHTML document with CSS selectors? I need to scrape some pages for data that is very easily accessible if I could somehow use CSS selectors (jQuery has spoiled me!). Any ideas?</p>

After Googling further (initial results weren't very helpful), it seems there is actually a Zend Framework library for this, along with some others:
DOM-Query
phpQuery
pQuery
QueryPath
Simple HTML DOM Parser
Ultimate Web Scraper Toolkit
Zend-Dom