Give your CPU cycles to a good cause
Most of us have in their home computers processors with loads of power, dual and sometimes quad-core monsters that most of the times are only used to render web pages, check email addresses or play the occasional videogame.
If you feel like giving your unused CPU time to a good cause, there is a nice piece of open-source software, called Boinc, that makes use of grid computing to solve complex scientific computational problems.
There are many sub-projects you can join after installing it, and you can pick the ones you want to donate your idle CPU cycles to. I have personally chosen “Help Conquer Cancer” and “FightAIDS@Home”, and I have set the Boinc program to run everyday between 2am and 7pm, when I am usually speeping or at work (and so my computer would not be used anyway).
Maybe it is useless, but I like to believe that sometimes, even something so little can make a difference.
If you want to know more about grid computing and Boinc, click here.