The one that i have used is at the below link. The only limitation is that i belive that it will not create a xml site map for sites that have over 500 pages. Enjoy http://www.xml-sitemaps.com/
I never used any sitemap before may be I have to use it now, thanks a lot for your useful resource, "blkg35".
Estateguy, it can be quite important, especially if you have dynamically generated pages, or pages that have odd ways of linking to them (i.e. through a java-driven nav bar which Google can't read). This will help Google find those pages, and give you credit for them.
If you use Wordpres engine, you could download SITEMAP PLUGIN, this is fully automatic for sitemap creation for Google, Yahoo and MSN.
I try this tool but it only includes only 500 pages in sitemap.xml file. My site have more than 500 pages then which sitemap generator tool I should use..
i also recommend xml-sitemaps.com ( and apparently so does google since they are at the top of the rankings.