1. TwitterSocial networking and microblogging service utilising instant messaging, SMS or a web interface.
Statistics Summary for twitter.com
2. PinterestPinterest is an online pinboard: a place where you can post collections of things you love, and "follow" collections created by people with great taste.
3. StumbleUponA web browser plugin that allows users to discover and rate webpages, photos, videos, and news articles.
Statistics Summary for stumbleupon.com
4. RedditUser-generated news links. Votes promote stories to the front page.
5. DiggTechnology focused news site where the stories are chosen by community members rather than editors.
Statistics Summary for digg.com
6. BuzzFeedAnd when you read BuzzFeed, you’ll always know the movies, music, and products that are on the rise and worth your time. You can join the fun by reading the latest at BuzzFeed.com, subscribing via RSS or email , adding the BuzzFeed widget to your site, and contribute by posting your own images, videos, links and comments. Be sure to sign up for a BuzzFeed account and stay tuned for more features coming soon.
Statistics Summary for buzzfeed.com
7. DeliciousDiscover Yourself!
, the world’s leading social bookmarking service.
8. MetafilterA weblog that anyone can contribute a link or a comment to. A typical weblog is one person posting their thoughts on the unique things they find on the web.
9. SlashdotA website based on and running the Slashdot-Like Automated Story-Telling Homepage software.
10. TweetMemeFinds the hottest stories from twitter for you to retweet. We make it easy for you to subscribe to each category and the most popular through our RSS feeds and Twitter accounts.
11. NewsvineUpdated continuously by citizens like you, Newsvine is an instant reflection of what the world is talking about at any given moment. Build a perfectly different, perfectly efficient way to read, write, and interact with the news.
12. DiigoDiigo enables effective collaborative research. You can easily share your findings, complete with your highlights and sticky notes, with friends and colleagues.
13. FarkSatirical views on interesting, bizarre and amusing stories, submitted by a community of millions of news junkies, with regular Photoshop contests.
14. FriendFeedEnables you to discover and discuss the interesting stuff your friends find on the web. Best Social Bookmarking Websites
15. Chime.inIs a social network based on interests, where people share, connect with others, and build communities around their favorite topics.
16. DZoneIs a technology publishing company that produces valuable content for software architects and developers worldwide.
17. FolkdSocial Bookmarking – Save your bookmarks and links online and search what your friends like.
18. BibSonomySystem for sharing bookmarks and lists of literature. Webapplication of the Knowledge and Data Engineering Group, University of Kassel, Germany.
19. ClipmarksYou can see clips of text, images or video about all sorts of topics that people find while surfing the web. Best Social Bookmarking Websites
20. BlinklistWe give you a browser button to “blink!” web pages you find in one click from your browser.