If you’re wondering why it takes 4 separate feeds to monitor Facebook, it’s because Facebook really doesn’t want to make it to easy on you. They’d much rather you spend your time logged into Facebook in your browser, seeing their ads while you play Farmville and Mafia Wars.
Note: see the “format=rss20″ bit at the end? It also seems to support “format=atom10″ as well, meaning RSS 2.0 and Atom 1.0 formats respectively. I couldn’t find any others that worked, including “rss10″, “rss” and “xml”.