Sitemap support from MSN, Yahoo and Google
google has really done a great job making sitemaps integral for any true SEO company and now it seems as if the other big two are following suit.
You can read more about it from Sitemaps.org, the homepage for this new initiative:
Sitemaps are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling. In its simplest form, a Sitemap is an XML file that lists URLs for a site along with additional metadata about each URL (when it was last updated, how often it usually changes, and how important it is, relative to other URLs in the site) so that search engines can more intelligently crawl the site.