How can my user make their own Blog/Diary

Question

It would be great if my Visitors could sign up and not only write comments, but also start their own diary.

Like user.mysite.com or mysite/user

Is something like that possible?

Answer 1

Yes, you can setup WordPress as a network/multisite, similar to the WordPress.com service.

You can find out how to do this here: http://codex.wordpress.org/Create_A_Network