Web logs, or blogs for short. On-line diaries, commentary, etc., etc.
Democratized News and Commentary-- This is very important given BIG MEDIA (see movies Orwell Rolls in His Grave or Outfoxed: Rupert Murdoch's War on Journalism.
Inspiring the disaffected to get involved in the political process and world affairs.
Educational Uses
Reader-filtered web.
Blogger, Google's Blogging system, is perhaps the easiest way to publish a blog.
Other publishing tools include Wordpress and Moveable Type.
Technorati is a popular site for searching and viewing Blogs.
Can search the entire blogosphere-- keyword search and url (what are blogs saying about a url)
watchlists
Others include Feedster and PubSub.
BlogLines -- Allows you to build your own personal news and blog reading site.
1. If you don't have a blog, create one using Blogger. Post an entry that has a reference to some web site URL.Add some uncommon words to the blog entry so we can find it later with a search engine.
2. Register at BlogLines. Select some of the feeds they provide. Also add your own blog as a feed. If your blog is a Blogger one, go to Settings | Feeds and you'll see the URL of your feed. Copy and paste it, then go back to Blog Lines, Choose Edit near your feed list, then choose Add and paste the URL to your blog.
3. Now let's see if Technorati has filed your blog. Go to technorati.com and enter the URL you posted about in the search box. Does your post appear? Try entering some text that appeared in your post. Does Technorati find your post?
4. Technorati Watchlists. Watchlists are like RSS readers, but instead of subscribing to a feed you subscribe to see posts from anyone but about a particular topic or URL. Get an account at Technorati, then add a Watchlist.
Beneath the Hood
The blog world works on a model called publish-subscribe and communicates with a language called RSS (Really Simple Syndication).
Basically, the blog publishing tool notifies (pings) services like ping-o-matic when you add a post. These services then notify aggregators like Technorati. Aggregators then download your post and index it so that others can discover it.
Sample RSS of Wolber's Blog -- http://cs.usfca.edu/~wolber/wordpress/wp-rss2.php
There's a number of RSS reader libraries of code that enable a program to process feeds.