Including custom add on domains in a sitemap

Is there any way to include extras in my site map. For example I now have a job board installed and would like to inlude the url's in my sitemap?

Another domain is a bad idea.... you want to 301 any double domains to the core domain. Otherwise, you're simply fighting yourself for ranking.

If this is just other urls from another program, you can add them in manualyl tot he extraURLs.txt file or create a custom script to do it dynamically in the addons folder.