1. Social Networks and Started by computer science students at Harvard University. One of the features of Facebook is that anyone is able to make an app and upload it. It is being made into a film, The Social Network, which will be released in 2010. Myspace was started in 2003 and is more focused on music. It was bought by Rupert Murdoch for $580 million.
2. Blogs More personal/conversational than social networks
Can vary hugely in content
Allow comments and RSS subscription
Many types including personal, political and mainstream media such as the BBC