Allows you to tell Google, Yahoo, and MSN if another page is the canonical, real URL to avoid duplicate content penalties.
Google released a new way to notify them of duplicate content so that it is not indexed and penalized. http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html
This plugin allows for you to link to another post or your home page from each post or page that is written letting Google know it is duplicate content.
This is a stable version.