I'm always intrigued by iPhone apps that try to do it all. Most of the time, it ends up being a "jack-of-all-trades, master of none." But, I always HOPE that someone can get it right.
This bring me to Ziibii [iTunes link]. It is basically a feed reader mixed in with Twitter, Facebook, Flickr and YouTube updates. And the way you read the headlines is in a most unusual way: Each story is on a "surfboard" that's flowing down a "river." You can always pause the river and swipe to see what's downstream. If you don't like the river view, you can choose to see it in a list.
This free app basically does what it says. Personally, I don't feel that the "river" concept is for me. I also don't feel that having Twitter comments mixed in with everything else really fits. If you see a Tweet you want to respond to, you'll have to get out of the app to do so. Also, YouTube doesn't work very well within the app.
Still, I would have to say that this is a very unique way of reading feeds. It's just not for me.