See related story: Man vs. Machine in Newsreader War

Reddit, a Boston startup, combines Digg-style voting with custom algorithms to figure out which stories you should be reading.
Screenshot: Courtesy of Reddit
Kevin Burton's Tailrank sorts through your blog and news subscriptions, then decides which are the most important bits.
Screenshot: Courtesy of Trailrank
Google News employs algorithms, not humans, to sort through news stories and tailors its code to your tastes using your clickstream and search history.
Screenshot: Courtesy of Google