It is well known that submitting your site to directories can benefit you by creating backlinks. Since the explosion of blogging online, directories have been created that cater only to blogs. Below is a list of directories obtained from the Google Directory exclusively designed for blogs along with the Page Rank of each blog. Not all are free, but they are worth checking out. I am going to go through these one by one and add Seanology to them in hopes to get more people reading my blog!

Lists weblogs by category. Users are invited to post reviews.
Blog Toplist
Categorized and sorted by popularity.
Blog Universe
Directory of weblogs as submitted and categorized by the site owners. Weblog, podcast, and video log directory.
Human-edited directory.
Research Blogs
An annotated list that can be used by researchers and academics.
The Ageless Project
Web logs by birthdate. Includes screenshots of the front page of each blog listed.
Kmax Blog Links
Alphabetical list. Links to weblog related resources. Top 20 ranking of the most popular and frequently updated weblogs.
Blog Watch
Categorized directory with latest post excerpts.
Listings by country and category.
Quick Blog Directory
Organized by category.
Alliance Of The Anonymous
Lists members who have posted the organization logo on their blog.
Allows users to rate listings in the directory.
Start4all: Weblogs
Startpage with links of webloggers. This page contains bloggers all over the world with interesting stories. Also links of famous webloggers and weblog tools, media, portals and meetings.
Delightful Blogs
Reviewed for personality.
Blog Ratings
Allows users to post and read ratings and reviews of sites organized by topic. Part of the Ratingz network.