Provides a sidebar widget containing links to posts with a similar set of tags to the current post.
The similar posts which are displayed are posts whose tag sets are similar to the tag set of the current post.
The widget displays on single pages only.
For example, if a post has the tags "foo", "bar", and "baz", and there are other posts in the system with the same tags, those posts will be displayed. If there are not posts that have all three, but some with two of the three, those will be displayed. The sort order for posts with the same number of matching tags is date.
Also allows the list of related posts to be added to the end of posts, or of posts in the RSS feed.