By looking at the sites I currently read in my homegrown news aggregator, looking them up in the blogging ecosystem and seeing which sites they link to, weighing them slightly by popularity (based on the natural log of their incoming links) but also dividing by the number of other sites they link to (because a midlist site that only links to a handful of people is more relevant than a popular site that links to 100), and filtering out sites that don’t have RSS feeds (plus a few I already know I don’t want to read), I came up with a list of recommended new reading.
You can point his project, NewDoor, to your blog or links page. His code is GPL’d, and can be found here: newdoor-1.0.tgz.