Sitemaps Ping URLs at Google, Yahoo, & Ask.com

 Sitemaps Ping URLs at Google, Yahoo, & Ask.com
Last week, Google, Yahoo, Microsoft & Ask.com To All Support Sitemaps Autodiscovery. So how do you ping these services to notify the search engines of an update to your Sitemaps, if you do not want to wait for them to find it themselves?
Softplus at Cre8asite Forums posted the URLs you can use to ping the various engines. Here they are:
Ask.com: http://submissions.ask.com/ping?sitemap=http%3A//www.domain.com/sitemap.xml
Google: http://www.google.com/webmasters/sitemaps/ping?sitemap=http:%3A//www.domain.com/sitemap.xml
Yahoo: http://search.yahooapis.com/SiteExplorerService/V1/updateNotification?appid=YahooDemo&url=http://www.domain.com/sitemap.xml
I did not test these myself, but they seem accurate.