VentureBeat has an article about a fun PepsiCo Visualization of SXSW related tweets,
And you can change the visualizations too. The default is a stream like Twistori, but you can also use “Popular” view, which is sort of like a tag cloud, “Swarm” view, which shows tweets on a map, “Party Watch,” which will focus on parties on any given night and “Overheard” view, which will seperate out all the tweets that start with “OH:”
Fun for checking out, although it seems that it’s rapidly being usurped by people looking for publicity & spamming the twitter-stream with bad data.