The Google Compute Project is an extension of the Google Search Bar that will add your computer to a network of others that are working on collaborative processing projects, ala the wildly successful SETA@home project. (No ETs found yet, though.) Google will use your computer to do computations during periods of time that it has extra processing power avaiable (such as when you are reading weblogs). Looks like they are donating the processing time to charities and/or academic research projects. (Via Google Weblog.)