Found very good information on Vikram's blog at,
As we all know the world of the Blogs work on the ping services. Once we update our blog with new posts we need to update the other sources that our blog has been updated. We should ping to the sources whenever we create or update our post.
Pings can be done both manually and programmatically. Many site provide free ping services for with a ping interface like http://ping.in/, http://pingoat.com etc. You enter your URL and and the feed title and they will ping all the ping server listed.
We can also ping programmatically. Programmatic ping is done through XMP-RPC Procedure, through which we send xml over the http request. The XML contains information of your feed and the URL to which you send the request is called the endpoint
Here is an example that I found that uses the xmlRpc Library from the cook computing.
Cool, Isn't it?