Since I have been using WordPress as my blogging platform I have used the Yet Another Related Post (YARPP). This plugin adds links to the bottom of each of your posts with related post topics. The plugin also adds links to bottom of your posts in your feed with related posts. There are lots of options that can be set up telling the plugin how to relate the posts, depending on tags and categories, and how old the related posts can be.
When I used Blogger I used LinkWithin. I liked the thumbnails at the bottom of each post linking to other posts within the site. I have also added LinkWithin to clients blogs over the last year.
Since I am addicted to changing things on my blog, last week I decided to ditch the YARPP and add LinkWithin. OK I did not ditch it completely. I left it installed to show up in my feeds since LinkWithin does not do that. But now below my posts you will see the thumbnails linking to other blog posts. If you click on it you will get a new post to check out. I have noticed a lot of my visitors have been using these visual thumbnails to find other topics to read.
I have seen a small increase in my pageviews per visitor, but I really like the vanity of LinkWithin. It dies not seem to load too slowly, and gives the visitors a nice image of the proposed posts. No LinkWithin does not relate the posts to each other, but the other benefits outweigh that factor for me.
You can set up LinkWithin and download a plugin for WordPress or install a code in blogger to utilize it. If you decide to use LinkWithin I hope you end up liking it as much as I do.