When a reply is made to a comment, a twitter notification (@twittername) will be sent to the original comment author to notify him/her of the reply. The notification will be sent from your Twitteraccount. 
This will allow the users to follow up on the comment and expand the conversation if desired.

CommentTweets

When a reply is made to a comment, a twitter notification (@twittername) will be sent to the original comment author to notify him/her of the reply.

Willy Bahuaud

“Mention comment’s authors” is a plugin that improves the WordPress comments fonctionality, adding a response system between authors. 
When adding a comment, your readers can directly mentioning the author of another comment, like facebook or twitter do,using the “@” symbol.
This mention plugin add two features :
<ul>
<li>In the comments field, when an user entered the “@” symbol, it allows, through an autocompletion system, to quote (or poke) a preceding commentator.</li>
<li>Once comments validated, the mentioned names take the appearance of buttons. When the user clicks on it, window scrolls to the preceding comment from the person named. A class is added to it, for temporarily customize it in CSS.</li>
</ul>
This WordPress plugin is based on <a href="https://github.com/tactivos/jquery-sew" rel="nofollow ugc">“jquery-sew” jQuery plugin</a>, by <a href="https://mural.ly/" rel="nofollow ugc">mural.ly</a>.
You can find more information on this post : <a href="http://wabeo.fr/blog/systeme-reponse-commentaires/" rel="nofollow ugc">wabeo : Un système de réponse dans les commentaires</a>

Mention comment's Authors by Wabeo

Helpfull to avoid nested comments and perfect for your SEO (I managed to remove a large number of useless links in my comments thanks to this plugin).
Bonus : A one-click setup ! ;)



Great tool

When adding a comment, your users can directly mentioning the author of another comment, like facebook or twitter do,using the "@" symbol.

CommentTweets vs Mention comment's Authors by Wabeo