Hi Tony,
Pings will be of the following format:
Code:
http://www.google.com/webmasters/tools/ping?sitemap=http://www.example.com/sitemap.xml
http://search.yahooapis.com/SiteExplorerService/V1/ping?sitemap=http://www.example.com/sitemap.xml
http://submissions.ask.com/ping?sitemap=http://www.example.com/sitemap.xml
To note but a few examples.
This is specifically for application to a site that has a healthy growth rate, and regularly updated content.
P.S. Don't get ping happy on this.. it'll result in being penalized.