What is a 'River of News' style aggregator?

I've talked about River of News style aggregators on Scripting News several times, and now would like to attempt a definition. Here goes.

Standard news readers organize feeds into groups, and then under each feed are items. If there's an unread item in a feed, the feed's name is bold. If you leave the cursor on an item long enough the feed name goes un-bold. These programs work much like mail readers, so much so that they are sometimes even integrated into mail readers.

But there's another kind of reader, an aggregator, that works differently, and I think more efficiently for the human reader. Instead of having to hunt for new stories by clicking on the titles of feeds, you just view the page of new stuff and scroll through it. It's like sitting on the bank of a river, watching the boats go by. If you miss one, no big deal. You can even make the river flow backward by moving the scollbar up. To me, this more approximates the way I read a print newspaper, actually it's the way I wish I could read a print newspaper -- instead of having to go to the stories, they come to me. This makes it easier for me to use my brain's powerful scanning mechanism. It's faster, I can subscribe to more, and my fingers do less work.

The first aggregator I wrote, in 1999, was a River of News style aggregator, and every other I've written since then. If you want to see a live example of one, check out the aggregator on the Share Your OPML site. Go back to it a few times today and you'll see what I mean. It's a very effective way to read the news.

Another metaphor -- conveyor-belt sushi 

Seattle Post-Intelligencer: "Conveyor-belt sushi is making the rounds in the Seattle area."

Discuss