Last Sunday I published a free plugin (License: GPLv2) in the wordpress repository, called WP Internal Links Lite.
With it, you can quickly and easily create internal Linking Structures over which you have absolute control (positioning, anchor texts, what posts link to which one...)
All the information, including a demo video, a screenshot and of course the download link can be found at the plugin's page in wordpress.org:
http://wordpress.org/extend/plugins/wp-internal-links-lite/
There's also a PRO version of this plugin, available at http://wpinternallinks.com, that removes certain limitations the Lite version has.
Mikel Perez