Did you know as of April 11th there was no longer a need to manually submit your sitemap to search engines. The major search engines agreed on a sitemap format. You can now add a simple line to your robots.txt file and let the engines know where your sitemap resides on your website.
Iinclude a similar line to this:
Robots.txt has traditionally been used to tell search engine spiders where go and where not to go on your website. This change in the robots.txt file allows you to tell the spider where to look for the sitemap file.
For more information about a robots.txt file just go to www.robotstxt.org