The symfony team have made it even easier to access all of the goodies inside their online version of their "The Definitive Guide to symfony" book (buy it). They've added keyword navigation to the right-hand side of the page to make searching simple.
Many impatient symfony users complained that the online version of the book missed the keywords sidebar. We didn't have time to rewrite it for the launch of the online book, but now it is repaired. Google is currently rebuilding its index of our website, so the search box in this sidebar will soon give relevant results again.