There are many free blogging services on the web. Below is a short list of some of the more popular services that can serve instructors and students well.

Blogger.com: Blogger is owned by Google, so if you have a Gmail account, you have access to Blogger. Blogger permits setting a publishing destination using SFTP, which allows your blog to be published back to your columbia.edu home directory. For example, your blog could be http://www.columbia.edu/~uni/blog/, where uni is replaced by your account.

Wordpress.com: Wordpress.com is from the same folks that created Wordpress, the open source blog tool of choice for many bloggers. Wordpress includes a free hosting option.

Edublogs.org: Edublogs is a Wordpress hosting company offering free blogs geared toward teachers and students.