I have created [login to view URL] that will automatically spider your website like the search engines do and upload 4 sitemap formats (Google, Yahoo, OPML, HTML) and I am adding a new format soon.
I offer free service with ad-support on the HTML sitemap or low monthly rates for increased spidering frequency, larger websites, and no ads at all.
AutoMapIt works on all websites regardless of your technology. It crawls your site as the search engines do.