Has anyone come across Pipes yet? According to their overview:

Pipes is a free online service that lets you remix popular feed types and create data mashups using a visual editor

What does that actually mean… well the first pipe I came across and have now cloned allows you to search all links found on a particular page so if you find a list of useful sites you can use this search tool to restrict your search to them.

My cloned copy of Tony Hirst‘s original linkedsearch pipe is set to search everything linked to from the CLT blog but you can change the URL to whatever you want. I’ve no way of knowing how well it works but it seems to pick up everything.
At the time of writing the most popular pipe is New York Times thru Flickr which finds photos (on Flickr) based on the current content of the NYT homepage.

Each pipe has an RSS feed too.  If you want to browse existing pipes, clone and tweak them or create your own from scratch head over to Yahoo Pipes