How to generate sitemap on a highly dynamic website?

Question

Should a highly dynamic website that is constantly generating new pages use a sitemap? If so, how does a site like stackoverflow.com go about regenerating a sitemap? It seem

Answer 1

I would only create a site map for the more static pages of the site. For example on StackOverflow a sitemap could showlinks for the FAQ, About, Questions, Tags, Users, etc... pages but not show links to the actual questions, or all the tags, and the various users.