I have released a new module : the iFinity Canonical Linker.  This module is an easy install and provides a complete solution for generating the Canonical Link Element in a DotNetNuke website.   It makes for a serious alternative to limited solutions that either use the requested url (therefore not eliminating duplicates) or that use a static html head inclusion (therefore eliminating content displayed via querystrings)

The Canonical Linker module works with all types of DotNetNuke Pages, including pages generated by content modules like the Blog or Forums modules, and third party content modules like e-commerce applications, video and photo galleries, and social networking applications.

The advanced configuration features allow you to filter out unwanted parts of urls to keep a constant 'canonical' url to show to search engines.  This module means you can create external links to your site and including tracking and affiliate variables, yet not cause duplicate content issues or be force to mess around with complicated redirects.

For a deeper explanation on DotNetNuke and the Canonical Link Element, please see the associated blog post : http://www.ifinity.com.au/Blog/Technical_Blog/EntryId/62/DotNetNuke-and-the-Canonical-Url-Link-Element/

To try out a free trial of the Canonical Linker software, please go to the Canonical Linker product page at : http://www.ifinity.com.au/Products/Canonical_Links_For_DNN/

The module is produced by iFinity Software, maker of the popular Url Master, Friendly Url Provider and Google Sitemap generator modules.