I am wondering if anyone has made an app in PHP that can look at a web
page and find a feed address on the page. This way, you could give the
aggregagor a generic root web address, and then have it detect and use
the feed address.

I see it could be done any number of ways. It could end
in .rdf, .xml, .php. I know that Firefox has a way to detect a feed on
a page, and it puts the orange feed icon in the bottom right corner of
the window.

Thanks.