jonkemp

Improves your blog’s search engine optimization by “noindexing” pages you choose.
Add the <code>noindex</code> robots meta tag to archives, categories, search pages, tags, author pages, login, admin pages or any other page you choose.
Add the <code>rel="nofollow"</code> attribute to individual pages listed by the <code>wp_list_pages</code> function or the Pages widget. Also, add the <code>rel="nofollow"</code> attribute to archive links, category links, registration and login links.
Changelog
*1.1.2 
**Bug fixes. 
*1.1.1 
**Bug fix where if user did not set nofollow pages, pages links would not display. 
*1.1 
**Added support for nofollowing login and registration links. Also, optimized some of the code. 
* 1.0 
**Added support for nofollowing individual pages in <code>wp_list_pages</code> function. 
* 0.5

Ultimate Noindex Nofollow Tool

Improves your blog's search engine optimization by "noindexing" pages you choose.

CyberNetikz

Just simple, if you use this plugin, <code>rel=nofollow</code> and <code>target=_blank</code> will be inserted automatically, for all the external links of your website posts, pages or theme menus.
Also you can set exclude domains, not to add <code>rel=nofollow</code> for the selected external domain links.
<blockquote>
If you need support, <a href="http://www.cybernetikz.com/wordpress-magento-plugins/wordpress-plugins/nofollow-external-link/#disqus_thread" rel="nofollow ugc">please leave your comment here</a>
</blockquote>
<h4>Feature</h4>
<ul>
<li>Add <code>rel=nofollow</code> for all the external links of your website posts / pages / menus.</li>
<li>Add <code>target=_blank</code> for all the external links of your website posts / pages / menus.</li>
<li>Support custom post type content.</li>
<li>Support WordPress multisite.</li>
<li>You can exclude domains, not to add <code>rel=nofollow</code> for the selected external links.</li>
<li>This plugin will not add <code>rel=nofollow</code> or <code>target=_blank</code> to any <code>href=#read-more</code> or <code>href=#gotop</code> type links.</li>
<li>This plugin will not add <code>rel=nofollow</code> or <code>target=_blank</code> any of the internal link on your website posts / pages.</li>
<li>If you already added <code>rel=dofollow</code> or <code>rel=nofollow</code> to any post manually, this plugin will not add <code>rel=nofollow</code> for that post.</li>
<li>If you already added <code>target=_blank</code> to any post manually, this plugin will not add <code>target=_blank</code> for that post.</li>
</ul>
You can visit our website <a href="http://www.cybernetikz.com/wordpress-magento-plugins/wordpress-plugins/nofollow-external-link/" rel="nofollow ugc">cybernetikz.com</a>
Wating for your valuable feedback/comments.
<h3>Support</h3>
<ul>
<li>[Plugin Homepage](* http://www.cybernetikz.com/wordpress-magento-plugins/wordpress-plugins/nofollow-external-link/)</li>
</ul>
<h3>Donations</h3>
Thanks for using this plugins

Nofollow for external link

Does exactly what it says!

Automatically insert rel=nofollow and target=_blank to all the external links into your website posts, pages or menus. Support exclude domain.

Ultimate Noindex Nofollow Tool vs Nofollow for external link