One of the big components we need for the loosely-coupled 140-character network are user interfaces for browsing rivers. 

That's the reason I published the JSONP version of my personal river, to help bootstrap the process by providing Javascript programmers a frequently updating stream of news to display. 

If you're working on a display, please post a link in a comment and I'll add it to this post. 

Right now I'm aware of: 

Martin Duffy's river viewer, the first to appear on this page. 

Ben Trask's entry in the River of News freestyle competition.  

Here's another from crashbang.co.nz. 

This is amazing: riverofnews.glowdart.com -- it's my personal river, flowing through the glowdart engine, thanks to JSONP. 

Hopefully, more to come.