Some Wordpress plugins are often updated, which is good think. Plugins that are updated are 100% compatible with last Wordpress version and they also are the most secure possible. A plugin that has not been updated for a long time might not work with last Wordpress version and might create a security breach for you website.
Use javascript to replace html tags with images to create image headlines.
Searches the text for links outside of the domain of the blog. To these, it adds class="extlink" (and optionally, target="_blank").
Breadcrumb-style navigation. Shows current viewing post or page, search results, category, and archives.
Allows easy addition to a post of a space-separated list of tags which can be displayed with adequate Technorati links in the template. Can display keywords instead if no tags are available.
Allows keywords to be associated with each post. These keywords can be used for page meta tags, included in posts for site searching or linked like Technorati tags.
Edit Comments is a simple WordPress plugin that allows commenters to edit their own comments. To edit a comment, a user must have the same IP address …
When activated, this plugin filters WordPress' output, removing redundant stuff from on-site links.
When someone is referred from a search engine like Google, Yahoo, or WordPress' own, the terms they search for are highlighted with this plugin. Packaged by Matt.