garo

Everytime you Publish a new post, this plugin will automatically 
send the update information to Pingler.com so the whole world can 
be notified that you keep your content fresh.

Pingler

This Plugin is used to automatically Ping new posts to a variety of online blogs. For use with Pingler.com

Rob Scott

The XMLRPC Pingback Ping can potentially be used as part of a DDOS attack. 
If you do not need the functionality, this plugin will use core functions to disable it.

Eazy XMLRPC Pingback Disable

This plugin disables the WordPress XMLRPC pingback ping.

Pingler vs Eazy XMLRPC Pingback Disable