chuoitaotau

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Description: 
A Related Posts plugin that is easy-to-use & highly customizable. Display list of related posts by tags & categories, let you decide number of related posts and select displaying content. Come together with two ready-built themes for your use!
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Features include:
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<li>Display related posts under posts with similar tags and categories</li>
<li>Custom number of related posts to display</li>
<li>Custom title, text size, and text color</li>
<li>Select content to display for each related post: post title, post thumbnail, author, create date, excerpts, and button Read More</li>
<li>Two ready-built themes for your use: Related posts with text-only and with thumbnail.</li>
<li>Related post slider: customizable number of posts visible at once</li>
<li>User can custom style for related posts</li>
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<li>Upcoming features:</li>
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<li>Responsive design</li>
<li>Related custom post types</li>
<li>Support widget</li>
<li>Custom post excerpts length</li>
<li>And more…</li>
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Quick related post

thumbnails are not displayed

Easy display Related Post under post by tags and category

husani

Searches various data sources (Google Blog Search and Twitter) for posts related to your content and displays links/summaries on your page or 
inside your posts. These links and summaries can be displayed anywhere and any way you wish — below your post, in a sidebar, etc. With the 
magic animation power of jQuery, SMIRC content can be hidden until a user clicks the customizable header.
SMIRC performs related content searching (at least in this version) by creating RSS feed URLs for the various data sources. The RSS feed is 
parsed and converted into XHTML for display in your blog.
All PHP is separated into logical classes and files, and all XHTML is standards-compliant. Lists of links, authors, and summaries are built 
using standard UL and LI tags, and can be modified to fit your theme via two CSS files contained within this plugin.
SMIRC is released to the WordPress community under the GPL. Please feel free to modify as you see fit, and if you find this plugin useful, donate 
to the author. All feedback is welcome at wordpressplugins@husani.com, and you can visit the author’s websites at http://www.husani.com and 
http://www.evb.com.
UPDATE FOR v1.1: Fixed a bug with setting header text.

Social Media Integrated Related Content (SMIRC)

Like trackbacks, but not -- this plugin searches and displays content related to your CONTENT, not just posts that link to yours.

Quick related post vs Social Media Integrated Related Content (SMIRC)