Will Brubaker

You’ve poured your heart and soul in to writing fascinating blog posts.  You know you have a lot of readership, but nobody except your mom is leaving comments.  That’s a bit discouraging right?  Entice your readers to leave comments by giving them a picture of a cute kitten in return.
Just prior to the comment form coming in to view, an unobtrusive panel will be displayed with a short message that says: “Your comments make us happy.  Leave a comment, get a kitten!”
 
When a comment is submitted, a picture of an adorable kitten is displayed in a modal window.
Caveats:
This plugin assumes that your comment form is A) built with the ‘comment_form’ WordPress function and B) that your comment form has an id of “commentform” (This is the WordPress default, but your theme developer may have changed the behavior for whatever reason. 
This plugin assumes that comment forms only appear on single posts and only loads the code when a single post (or page) is loaded. 
 
<h3>Other Information</h3>
I created this plugin for my own amusement and am offering it for you to use as you wish.  If you find it useful but would like more features, please do ask.

Kittens for Comments

Works well, customizable and just damn cute! Love it. =D



Awesome

Encourages your readers to leave comments with the promise of a kitten picture.  Who doesn't love kittens?

InContext

Comments are extremely critical for the success of a blog. All existing blog platform and commenting plugins only let readers add comments all the way at the bottom of a post, out of the context of the content in the post. When you write a long blog post with, say, 10 paragraphs, and readers are commenting on a particular statement or expression in paragraph 3, they have to scroll back and forth to read the context to figure out what the comments are about. The “In-Context Comment” plugin changes that: Now you can add an “In-Context Comment” icon using <in-context-comment:here:tag> (where “tag” is any word or words connected by hyphen ) at any place you want readers to comment on and they will be able to click and open a window to add comments right there, next to the context so other readers can see both the context and the comments in one glance. The comment window automatically closes when a reader clicks the cursor anywhere outside the comment window so it does not interfere with the reading.
This plugin can also help you grow your readership by posting the comments to the commenters’ Facebook and Twitter status updates to bring in new readers to your blog. 
You can also configure the “In-Context Comment” plugin to automatically add a comment icon at the end of each paragraph that is longer than a certain number of characters. This auto feature is enabled by default with a minimum character count of 360. Please go to the plugin’s Settings page to change.
<h3>Documentation</h3>
Visit http://wizag.com/incontext.php for example and documentation

In-Context Comment

"In-Context Comment" lets readers leave comments right next to the content being commented, instead of only at the bottom of the blog post

Kittens for Comments vs In-Context Comment