I joined the blog promotion community The Goodblogs today. Although I'm a new user, it works well. Goodblogs is still developing new features that promise effective promotion of blogs.
I installed a widget into my sidebar listing good-blogs from categories I've selected. I can join communities where I want to be listed in. This gives me exposure to other peoples blogs. The widget displays the title of the blogs and a short note from the latest post.
A very cool feature is that I can click on the widget, change the blogs that are displayed, as well as see titles or not etc. This feature adds interest to the traditional blogroll.