Just a reminder, you no longer have to go to Google or Yahoo to submit your sitemap file location manually. The major engines have (mercifully) agreed to a common sitemap protocol that allows the spiders to find your sitemap file by way of your robots.txt file (for a change, robots.txt tells the spiders where to go instead of where NOT to go).
Just place this line in your robots.txt file and you’re set:
Naturally, you need to change the yourdomain.com to whatever your actual domain is.
Sitemap files are terrific for getting all of the pages on your site found by the search engines. If you’ve got a large site and want a free way to spider it and generate a sitemap for you, take a look at SiteMapBuilder.net.