There has finally been an enhancement to the standardized sitemap protocol developed by Google, Yahoo and MSN – Autodiscovery. Autodiscovery gives siteowners the ability to easily share their sitemaps with all search engines at once, avoiding the overhead of manually submitting them to each search engine.
The protocol works as follows. Add the following line to your robots.txt file:
This is an important addition, yet not the end all be all for sitemaps. I know MSN had stated they have not yet planned on viewing this protocol but will in the future.