There is a way to throttle down the CPU usage. I won't cut and paste the post but it is discussed at length here:
World Community Grid - Error !!!
I'm glad you mentioned it because even though my fan is silent I'm not keen on keeping the CPU pegged just from a "wear and tear" point of view.
Now that we broke the 1000 mark what is the next goal? I know that some of the groups have hundreds of computers on the grid so what is our maximum realistic rank with the number of machines we have online?