not all sites have them.. Ususaly a search at
www.google.com will turn up something..
And some are not available to the public... HardOCP.com has one but its only accessable by other websites via a PHP script...
Just a note.. if the RSS file does not display in your browser it will not likely work with the trillian plugin.
the CNN one does not seem to be public, just like the HardOCP.com ....
Lots of sites don't like haveing them public because they charge other sites for them or they get too much traffic from all the timed downloads.