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.

michas.n@gmail.com

SofA is a SEO plugin where you can exchange external links betwen SofA users. 
SofA will connect you with different users having similar content and will allow you to turn into links with them. 
You can Exchange your content now and build external links network. SofA is the biggest network where you can share your content with different people around the world. 
You can write posts which contain links to your page and add to SofA repository. 
Someone else will publish your post on then Blog and will give you external link to your page. 
SofA will find right person for you. Based on your tags and tags from another people we merge people in smaller groups. 
Every one in the group can read your post. 
When someone decide to publish your work we will remove your article from SofA repository to protect users against duplicate content issue. Build popularity using external link network.

SofA

Set of Articles - Exchange external links

External Permalinks Redux vs SofA