Blogger.com – A great starting site to get a taste of blogging, very easy to use.
Blog.com – Offers free blog hosting with unlimited bandwidth for their free package, more benefits for paid members.
WordPress.com – Not only can you install WordPress on your own sites, you can use the same software on their site and save yourself all of the technical work.
Tumblr.com – A blog platform with a focus on allowing media-rich posts.
Blogsome.com – WordPress based platform.
Edublogs.org – Free EDU blog for students and teachers.
Blogdrive.com – Free web blog host.
Blog.co.uk – Free blog.
Blogstream.com – Free Blog For everyone!
Xanga.com – Part social network, part blogging, all free.
Yahoo 360 – Part of your Yahoo account and features easy publishing.