Trst.me (from Infochimps) relies on calculating user reputation instead of just seeing how many followers they have as a deciding factor. The first thing I noticed about how they compile the information is that they have been compiling Twitter information since 2008 using the API. This gives them a good base to begin measurement.
You enter a username into the single box on the page to have it compute a score ranking of 1-10. Our president of the US holds the highest rating at 9.9, which is .2 higher than CNN. But Ellen Degeneres and Shaq are not far behind. Scary isn’t it?
They also give a good comparison of their service and other Twitter user ranking services and how they differ.
Don’t worry, you won’t rank as high as you hope.