Klout has been one of my go to punchlines for some time now. For example - in May I wrote a post titled "My Detailed Thoughts On Klout" that contained a single word in the post itself: "Why?"
The problem I had with Klout was that it was just another meaningless social game to play. People were wrecking their heads trying to game it and get their score up higher.
Here's an interesting turn-of-opinion from Michael Arrington, a previous detractor of Klout. AS an update to my post earlier this year on whether Klout matters of not, the answer now appears to be "Maybe not yet, but soon." It will be interesting to see how Klout's new algorithms and data points actually play out and whether that actually succeed in making Klout meaningful.