After Web 2.0, cloud computing is the latest buzz word in the industry. I remember IBM started started implementing first Grid computing architecture just a few years back and not its turning into widely accepted reality. Now we can say by and large that cloud is evolved from grid computing to fairly matured model. Amazon has become pioneer by launching their AWS suite. Still this idea has a long way to go... Actually this is going to be debating topic if "grid computing" in cloud or cloud in "grid computing". ...each cloud can be made up of grids and all clouds can be in turn connected in outer grid! I think it really depends on how one visualized the things. But clearly the bottom line is to leverage the power of computing so that now instead of focusing more on building faster chips, industry can shift the focus on building efficient cloud and faster connectivity. I am sure roughly 50% of the machines of the world (probably more after considering huge redundancy