Although the SEO value of link directories have eroded over the past few years, there might still be value for niche-specific link directories and
well-indexed directories. The plugin below lets you build a link directory using Wordpress
Might be useful for A > B > C types of link trades (although you'd probably need a link verifier to monitor your link trade partners)
http://wordpress.org/extend/plugins/business-directory/
The demo is located at:
http://businessdirectory.squarecompa...ple-directory/