There is a really interesting analysis from O’reilly Radar on who the top #SXSW twitter champions have been over the past 3 years. I find this to be a very interesting case study of how to use the twitter stream for research and analysis. Take a look:
http://radar.oreilly.com/2011/03/sxsw-champion-2011.html

Their summary of what makes a champion is right on:
* retweet
* share messages
* respond in real-time
* provide useful information on topics that are interesting to their followers

Good advice for anyone trying to build a brand on twitter!