Digg is a huge social bookmarking site which allows users to share what they found with their friends. Users of this site can then rate it, either giving it a digg or to bury it. Submitting webpages to Digg is simple, just login to your account and add a story. Some sites come with a script for you to automatically add the webpage to Digg. And what is a social networking site without the ability to comment on articles? Just login and say your piece. However, Digg is moderated so it will be less prone to abuse. All the services are provided free to their users.