just signed up my site with Google Webmasters and im trying to create a Sitemap XML file.

I assumed as it is just an XML file that Google would provide a web based generator tool to generate this automatically. but it seems that they do not, and after goggling a "Google Site map generator", nothing obvious was revealed.

After reading the google help, it recommended a SiteMap based on the “sitemap protocol” as this is supported by Bing and other search engines

what I’m looking for is and links to apps or web based site map generators that will crawl my site and create the XML.

My site has 1000’s of pages so I certainly don’t want to have to create this manually!

Any help is most appreciated