Classmite is a site that gives you the ability to write articles that will help someone. They can be a story, a tutorial, a news article or whatever, that you would otherwise need to create a blogging site for.
You will also read what others have written and comment on their posts.
The site also has forums where discussions are held. The topics for these forums are created by registered users, and they can be of any topic.
To visit the site and explore, you can follow this link.
Here are a few screen shots of the site: