According to CNET News Google, Yahoo and Microsoft teams up on using the Sitemap protocol. The Sitemap protocol is an XML standard for describing the site content and the update frequency to make it easier for search engines to crawl a site.
This is great news for all site developers and owners to have their sites crawled correctly.
The only problem so far is that you have to submit the Sitemap to each and every crawler that supports the Sitemap protocol.
I think there should be a HTML LINK rel option, so that you can use HTML like this on your site and have the crawlers check for the tag:
link rel="Sitemap0.90" title="Sitemap" href="http://www.company.com/sitemap.xml/>