What is social bookmarking?
Social bookmarking sites allow you to store, and share links across the internet, meaning that if you see a page on RFU.com that you want to share with other people, or save for future reference you can click on one of these links to add it to your list.
These sites are free to use but require you to register. Once you have registered you can begin bookmarking, saving and sharing links.
Del.icio.us
Delicious is a social bookmarking service, which means you can save all your bookmarks online, share them with other people, and see what other people are bookmarking. It also means that you can see the most popular bookmarks being saved right now across many areas of interest. In addition, the search and tagging tools help you keep track of your entire bookmark collection and find interesting new bookmarks from people like you.
Digg
Digg is a place for people to discover and share content from anywhere on the web. From the biggest online destinations to the most obscure blog, Digg reveals the best content as voted by its users.
Reddit
Reddit is a source for what's new and popular on the web. Users provide all of the content and decide, through voting, what's good and what's not. Links that receive community approval bubble up towards number one, so the front page is constantly in motion and filled with fresh, interesting links.
Facebook
Facebook is a social utility that helps people communicate more efficiently with their friends, family and coworkers. The company develops technologies that facilitate the sharing of information in people's real-world social connections. Anyone can sign up for Facebook and interact with the people they know in a trusted environment.
StumbleUpon
StumbleUpon collates ratings from its users to form collaborative opinions on website quality. When you stumble, you will only see pages that friends and like-minded users have recommended. This helps you discover great content you probably wouldn't find using a search engine.