Free blogging systems

Blogging is a great way of communicating with the users, it is a great way to keep them updated or to develop a community. There are several systems that allow users to blog for free.

This system offer the user the option of creating a subdomain with a name they choose and then start blogging rightaway. Many of these systems allow direct linking so they can be useful not just for communication, but for link building also.

It would be nice to create a list of the ones not everyone knows about.