Social News Sites
Digg: is the most popular social news site with a variety of topics. It has an easy-to-use interface and new users can be up and running in no time.
Propeller: was formerly a part of the Netscape website. Its interface is bit more busy than Digg's, but it does have a handy control panel that will list out related articles while viewing a specific article.
Reddit: is the no-thrills social news site, and also very popular. It is plain bordering on downright ugly, but it is very easy to use.
Newsvine: is a social news site following a newspaper-style. It is fed by news feeds like the Associated Press. It also allows users to write their own articles and create their own columns.