Yahoo Buzz is Social Bookmarking site which rank stories based on people’s liking. It is becoming more and more popular as it provides the facility to Discover, vote, comment and submit.
StumbleUpon.com helps users discover and share good websites on the Internet by ‘Stumbling’. It is a Social Bookmarking site which focuses more on sharing.
Propeller.com is more like Social News portal which rank news based on People’s interest shown. Propeller is becoming more and more popular.
Mixx.com is a Social Bookmarking site which lists stories, photos and videos as per user-recommendations.It provides a platform for rating different content.