@Prometeu
http://en.wikipedia.org/wiki/Ping_(blogging)

Ideea de baza: un blog notifica un server prin protocolul XML RPC ca are continut nou.

ping is an XML-RPC-based push mechanism by which a weblog notifies a server that its content has been updated.
Sunt o gramada de pagini care se pot pingui, pingomatic.com aduna cateva si permite notificarea lor printr-o interfata simpla.