MindTouch has recently analysed Knowledge Management influencers and produced a top 100 list.
They add the caveat that they know there are several profoundly influential people not represented on the list and that it should be clear that the list constitutes a core group of influencers in the KM space on Twitter.
I am honoured to be number two on the list but take it with "a big pinch of salt" - ignore the order and it's not too difficult to spot anomalies but if you are looking for KM people to follow its a good resource.