How would this work ? There could be a video server that would allow me to put a video on my blog (like google video) or a simple game or whatever thing that people would enjoy and spend a little time doing. During this time there would be a package downloaded from the same server, some processing done on the client side and a result sent back. If people enjoy the video/game/whatever and it goes viral then it spreads all over the blogs and any person dedicating their attention to it is contributing computer power to solve some task. Maybe this could work as an alternative to advertising ? Good content would be traded for computer power. To compare, Sun is selling computer power in the US for 1 dollar an hour. Of course this type of very small scale grid processing would be worth much less.