Instant RSS Search is a Google powered feed engine to help you discover RSS feeds around your favorite topics. Try one of these sample search queries:

tech news - find RSS feeds of all the popular blogs and news websites that cover technology related topics.
site:thenextweb.com - find all the RSS feeds offered by your favorite web publisher (like thenextweb.com).
edward snowden site:nytimes.com - find all RSS feeds around a particular topic from a single website (like The New York Times).
allintitle:revision3 - find podcasts feeds from Revision3.
google inurl:twitter.com - find all the official Google accounts on Twitter.