I was doing a little work on a tool I wrote in April 2007 that pushed RSS content to Twitter, and made a simple enhancement: instead of having a Twitter account reflect the content of a single feed, I made it reflect the content of an arbitrary number of feeds.
This let me do something I've been wanting to do for a while, but never thought of using Twitter for -- I set it up to reflect the content of my blogging friends, people like Doc Searls, Scott Rosenberg, Scoble, Andrew Baron, NakedJen, Michael Gartenberg, Marc Canter and a few others. Not sure if this is going to amount to anything, but I thought it was worth noting. The tool is twitterRiver.root, and the feed it's associated with is friendsofdave:
http://twitter.com/friendsofdave
You may of course choose to follow this feed if you find it interesting, and I will probably release the tool at some point in the future.