I like tracking my "dot" on the Klout graph, and looking at some of the analytics. However, I find that Klout seems to base its assessment of my "influence" on a very small number of specific tweets that I sent a very very long time ago. I am not convinced it offers an up to date view of the Twitter influence landscape.
Article explores the implications of how people use Facebook recommendations and links to find info on other sites. Will Facebook replace Google? Who knows, but speculation abounds.