mikegogulski

Pingcrawl aims to replicate WordPress.com’s “Possibly related posts” capability. It queries Google Blog Search for related blog posts (based on tags, or the post title if there are no tags), tries to verify that they are pingback/trackback compatible sites and, if so, adds links to such posts to the end of each blog post where it is invoked.
Scope-limiting configuration options are included to enable Pingcrawl to fit any WordPress installation’s memory/execution time budget.
<h3>Licence</h3>
Pingcrawl is free software released under the GPL. If you find it valuable, you’re invited to make a <a href="http://www.nostate.com/support-nostatecom/" title="Donate with PayPal, MoneyBookers, etc." rel="nofollow ugc">small donation</a> toward its ongoing support and maintenance.

Pingcrawl

Pingcrawl adds a "Possibly related posts" capability by querying Google Blog Search for post tags and pinging the results.

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.

Pingcrawl vs Force Ping Display with Disqus