Of course, most website analytics tools will give this information to you anyway, but if the tool you use doesn't have this feature, then it's always nice to get it for free from Google. But the best part of the Sitemaps program is ... If you already have a Gmail, Adsense, or Adwords account, then you are all set. If not, you can register an account by visiting the Google Accounts page (https://www.google.com/accounts/NewAccount). Building your sitemap file is pretty easy ...