Social bookmarking is a way of storing, organizing, and sharing links to resources. You've probably bookmarked websites on the browser of your computer; social bookmarking allows you to store your bookmarks on the Internet, and retrieve them anywhere you have access to the Web. You can also "tag" your bookmarks to help organize and retrieve them. For example, if you bookmarked the homepage of your favorite TV show, you might give it the tags television, favorites, and comedy. You could then pull up the bookmark with any of those three tags.
There are dozens, if not hundreds, of social bookmarking services available. At the Thompson Library, we are using three of them: Delicious, Netvouz, and Diigo. We use Delicious to provide "linkrolls," i.e. dynamic lists of bookmarks on the Thompson Library website. All our bookmarks are also bookmarked in Netvouz and Diigo as backups, in case Delicious goes down due to maintenance or malfunction. For finding free websites that students and faculty might find useful, we provide tag clouds on each of the subject pages.
Social Bookmarking in Plain English
This video focuses on Delicious, but the underlying concepts apply to other social bookmarking services as well.