Google sitemap is one of the way get quickly and regularly indexed in Google database and there are many companies offering various scripts for generating sitemap. Google has also one python script which is now three year old.
Google now introduced a new site map generator a sit is of the opinion that others scripts only make the list of url in site on the basis of server data.
We have created a different kind of Sitemap generator that uses several ways to find URLs on your website and then allows you to automatically create and maintain different kinds of Sitemap files.
Webmaster should take the advantage of this tool