http://www.google.com/webmasters/sitemaps/ping?sitemap=http://www.example.com/sitemap.xml
http://api.search.yahoo.com/SiteExplorerService/V1/updateNotification?appid=YahooDemo&url=http://www.example.com/sitemap.xml
http://submissions.ask.com/ping?sitemap=http://www.example.com/sitemap.xml
http://api.moreover.com/ping?u=http://www.example.com/sitemap.xml
http://webmaster.live.com/ping.aspx?siteMap=http://www.example.com/sitemap.xml