At a Recent conference Google, Yahoo and Microsoft announced have all agreed to standardize on the sitemap standard that Google launched almost a year a go.
The XML sitemap format the Google developed is a way for website owners to publish a definitive list of pages on a website to allow search engines to find odd or hard to index pages. Google also have extended the system to provide additional stats and diagnostic tools that make a Google sitemap a very useful tool for any webmaster or SEO.
recommend using an xml sitemap as one of the initial stages in optimizing a website for several reasons:
1: It provides in valuable statistics and diagnostic information on how a particular search engine is interacting with your site
2: For existing sites with a large number of pages it can help search engines discover pages it does not already know about
3: Googles sitemap tool does give warnings about possible penalties for violating their guidelines
It will be interesting to see what additional tools Yahoo and Microsoft will provide of the back of using the sitemaps format (you can submit an xml sitemap to yahoo Microsoft’s offering is yet to be launched)
A video of the announcement is here. Also the new home for the sitemaps standard is at sitemaps.org Google have also put the sitemap standard into the public domain.