Instead of turn­ing off your com­puter, you could use it to help fight dis­eases such as AIDS and can­cer with World Com­munity Grid. Its a dis­trib­uted com­puter pro­gram that uses many stand­ard com­puters to per­form the same task, col­lect­ively, as a super com­puter. By using the spare CPU cycles of your com­puter, it can even sur­pass the pro­cessing power of a super com­puter, and hardly make an effect on your pro­ductiv­ity or the speed of your computer.