Upgrades the next/previous post link functions to reorder or loop adjacent post navigation links, display post thumbnails, and customize link format.
IMPORTANT: Make sure you are using the right plugin.
The two plugins have similar sounding, but different, function names. If you mistakenly install the wrong plugin, you will get a "call to undefined function" error. If you want to create next/previous links for your pages, please check out: http://wordpress.org/extend/plugins/ambrosite-nextprevious-page-link-plus/
IMPORTANT: This plugin is not compatible with PHP 4. If you try to install it on a host running PHP 4, you will get a parse error. WordPress has officially ended support for PHP 4 as of version 3.2, so you should upgrade to PHP 5.2 now. For those who cannot upgrade, you can download the alternate PHP 4 compatible version of the plugin. The only difference with the PHP 4 version is that the %category variable will not work with custom taxonomies. http://www.ambrosite.com/download/ambrosite-nextprevious-post-link-plus.php4.zip
This plugin creates two new template tags -- next_post_link_plus and previous_post_link_plus -- which are upgraded versions of the core WordPress next_post_link and previous_post_link template tags. The new tags include all of the functionality of the core tags, plus the following additional options:
Extensive documentation on configuring the plugin may be found here: http://www.ambrosite.com/plugins/next-previous-post-link-plus-for-wordpress