Erick Hitter

Oomph, Inc.

Allows users to point WordPress objects (posts, pages, custom post types) to a URL of their choosing, which is particularly useful for injecting non-WordPress content into loops. The object appears normally in any loop output, but visitors to the object will be redirected to the specified URL. The plugin also allows you to choose the type of redirect, either temporary (302), or permanent (301).
Through a filter, the External Permalinks Redux meta box can easily be added to custom post types. There is also a function available for use with WordPress’ <code>add_meta_box</code> function.
This plugin was originally written for use on WordPress.com VIP. It is inspired by and backwards-compatible with Mark Jaquith’s Page Links To plugin, meaning users can switch between plugins without risk of losing any existing external links.
This plugin is translation-ready.

External Permalinks Redux

Allows you to point WordPress objects (posts, pages, custom post types) to a URL of your choosing.

Peadig

rel=”external” is now the XHTML valid version that informs search engine spiders that the link is external. However, using this does not open the link in a new window. target=”_blank” and target=”_new” does this, but is not XHTML valid.
This very simple plugin adds a small JS file to your header to let this happen!
<ul>
<li><a href="http://pleer.co.uk/wordpress/plugins/rel-external/" rel="nofollow ugc">rel=”external”</a> plugin homepage.</li>
<li>More <a href="http://pleer.co.uk/wordpress/plugins/" rel="nofollow ugc">WordPress Plugins</a>.</li>
<li><a href="http://pleer.co.uk/wordpress/plugins/facebook-comments/" rel="nofollow ugc">Facebook Comments</a> Plugin</li>
<li><a href="http://pleer.co.uk/wordpress/plugins/wp-twitter-feed/" rel="nofollow ugc">Twitter Feed</a> Plugin</li>
<li><a href="http://twitter.com/alexmossSEO" rel="nofollow ugc">Follow @alexmossSEO on Twitter</a>.</li>
<li><a href="http://alex-moss.co.uk/" rel="nofollow ugc">Alex Moss</a>.</li>
<li><a href="http://pleer.co.uk/" rel="nofollow ugc">Pleer SEO</a>.</li>
</ul>

rel=”external” in a New Window

Opens a new window with rel="external" instead of having to use target="_blank" or target="_new"

External Permalinks Redux vs rel=”external” in a New Window