Add 16×16 favicon after all the links in your posts. 
The favicon’s tag has a ‘favlink’ class so you can CSS it as you wish.

Karedas Favicons

Adds corresponding favicon from Google Shared Stuff after every links in your posts.

epipe-com

This plugin adds a favicon link to the document head section.
There are no options. The link is always added when the plugin is enabled.
The <code>favicon.ico</code> file needs to be uploaded to the site’s root 
directory. If you do not know how to do this, you should have a look at 
one of the other favicon plugins.

The Simplest Favicon

Adds a favicon link to the document head section.

Karedas Favicons vs The Simplest Favicon