see here: http://www.joomlaspan.com/general/the-best-sitemap-generator.php ^^ http://joomla.vargas.co.cr/sitemap
New sitemap for Joomla 1.5 with PingBack system - SEF Service Map 2: http://extensions.joomla.org/component/option,com_mtree/task,viewlink/link_id,6563/Itemid,35/ Regards, Radek.
I use xml-sitemaps then submit my sitemap to Google Webmaster Tools. It shows me any errors and also when the pages get indexed.
My favorite XML Sitemap generator http://www.web-site-map.com/ has gotten some very nice Joomla support recently. And it's still free - as before