use robots.txt to get your sitemap automatically discovered by search engines

Since 4.5.2 DotNetNuke has had the capability to automatically generate an xml sitemap  , a useful way to help search engines index your website. Typically you have to go to a website such as www.google.com/webmasters/tools to submit your sitemap url, however theres an easier way to do this. Search engines will automatically check for the existance of a robots.txt file in your site root to see what sections of a site are allowed to be indexed. A number of the major search engines such as Live, Google, Yahoo and Ask also support picking up the locations of sitemap's via an autodiscovery instruction. To save yourself the effort of manually registering your sitemap page, just create a robots.txt file and add a line such as:

Sitemap: http://www.yourwebsite.com/sitemap.aspx

The next time a search engine that supports autodiscovery browses your site they will see where the sitemap can be found and use that to help index site content.

Note: whilst the core sitemap does a good job of indexing pages, there are a number of other community donated sitemap's that work well with dynamic modules, the http://www.dotnetnuke.com/Community/Forums/tabid/795/forumid/108/threadid/207139/scope/posts/threadpage/1/Default.aspx thread has some good information on this.