Jeremy Wagstaff recommends BlogBridge:
On one level it’s just another (free) news reader. It lets you collect and organize RSS feeds into folders according to theme (Technology, Sport, Squirrel Waterskiing, etc.). But BlogBridge goes further.
First off, BlogBridge calls its folders “Guides” or “Reading Lists.” These aren’t just static collections of feeds, but are lists carefully collated by experts in the relevant fields, whose credentials you can read on the site. Instead of subscribing to a single feed, you subscribe to an expert’s Guide or Reading List. Conversely, if you felt you were an expert on Squirrel Waterskiing, you could share your list of exciting blogs and other feeds on the subject as a Reading List, allowing other Squirrel Waterskiing enthusiasts to download it into their BlogBridge program.
Nothing too revolutionary here, since it is already possible to share groups of feeds, although only really for the seriously nerdy fringe. But one of the neat tricks with BlogBridge is that any Reading List you subscribe to can be dynamically updated.