Seth Godin makes yet another interesting observation on his blog about "Bobcasting", where RSS meets the truly personal.
Today, most RSS feeds are one-to-many; it's quite possible for RSS feeds to be much more 1-to-1.
For instance, on BigOven, you can subscribe to your friend's "Recipe Streams", to be alerted to the photos they post, their Try Soon Recipes and Favorites, and what recipes they rate. If you know a friend or two that eats the way you want to, it's a great source of 2:00pm "what should I make tonight?" inspiration.
See mine at http://www.bigoven.com/~stevemur.