pontocinza

When a post is published or updated, Internal Pingback Comments scans its content, finds all internal links, and creates a pingback-style comment on each linked post. It mimics native WordPress pingback behavior but eliminates the need for XML-RPC or outbound network requests.
Works with posts only. No settings page, no configuration.
How it works
The plugin parses post content with DOMDocument — not regex — so it handles real-world HTML correctly: nested tags, encoded entities, relative and protocol-relative URLs. For each internal link found, it inserts a pingback comment on the target post. The comment includes a short excerpt from the source post, with image captions (figcaption) stripped so they do not bleed into the pingback text.
Duplicate detection is precise: the source permalink is stored as private comment meta, and the plugin queries that meta before every insert. Republishing or updating a post never creates duplicate comments. New links added to an existing post will generate their own pingbacks on the next save.
What the pingback looks like to your theme
The comment is stored with <code>comment_type = 'pingback'</code> and auto-approved. Your theme renders it exactly as it would render a native pingback. If your theme does not display pingbacks, the comment will be stored in the database but remain hidden on the front end.
<h3>Disclaimer</h3>
This plugin is provided “as is”, without warranty of any kind. While best efforts have been made to ensure reliability and security, the author is not liable for any damages or losses resulting from its use.

Internal Pingback Comments

Detects internal links in posts and automatically inserts a pingback-style comment on each linked post. No XML-RPC required.

Speeddymon

Shows Pingbacks and Trackbacks above Disqus comments.
All credit for the functionality of this plugin remains with the original creator, Marco Luthe of http://www.saphod.net 
Additional credit to Scottsdale Computing (http://theitbros.com) for some formatting changes they made when posting this on their site 
This was originally created as a theme modification. It has been turned into a plugin by myself, Thomas Spear.

Force Ping Display with Disqus

Shows Pingbacks and Trackbacks above Disqus comments.

Internal Pingback Comments vs Force Ping Display with Disqus