Add sharing buttons to your blog posts for: Facebook, Digg, Twitter, Email, Reddit, StumbleUpon, etc.
TagMeta - Using your tags as meta keywords.
Wordics creates colorful word clouds from the text in your blog. They are summaries of your blog posts in the way search engines would do them.
Set user specific time zones; this is a work in progress.
A plugin that builds a tag cloud using content from one or more blogs or other websites that provide an RSS feed.
Hide posts with certain tags/categories from the public and other authors
Adds a shortcode for internal links to tags, but checks if the tag exists before linking it.
Creates a template tag that generates a link to an RSS feed for any given tag, optionally allows the inclusion of copyright information into RSS feeds
Provides a sidebar widget containing links to posts with a similar set of tags to the current post.
Event Tags is a plugin for wordpress which generates a link to a Last.FM event page from machine-tagged posts.
This plugin was extended from Matt's Community Tags and it allows the community to add tags to your posts. The tags should be added with commas and on
Creates links automatically from #tagname or @username anywhere within your blog posts, pages, and comments
Stylish Indexes for your WordPress Blog. Create alphabetical indexes of your posts, with headings, subheadings, and descriptions, based on post title,
CommentSafe is a very simple plugin which removes (X)HTML tags you specify from your comments.
This plugin will tie a tag to a single post or page, via the ID.
RSS link for this tag.