Distributed computing is one of the wonderful ways that you can use your PC to contribute to more thoughtful, worldly causes than keeping your room warm during a cloudy summer day. These projects, made up of members from all corners of the world (even Maximum PC's own forums), make use of your computer during its idle periods. Whether they're come as a screensaver that launches after a set period of time, or a background application that launches after a certain period of CPU inactivity, these free applications divvy out the tasks of a large, complicated project to a number of people at once.
Why should you care? Because distributed computing is a nice way to use a minimal amount of your system's resources--resources that you wouldn't be using anyway--to contribute to something greater than yourself. It's entirely altruistic in its purpose. Very, very few distributed computing projects have some kind of monetary award attached to the work, and you'd have to score a major knock-out in your individual contribution to the project to see the result. That is, your computer would have to be the one that finds the next huge prime number, or major breakthrough in protein analysis, or something to that effect. If you're in it for a reward, you might as well develop a program that estimates lottery odds.
You'll find that entities like Maximum PC, amongst others, have teams of people contributing to these distributed computing projects. It's a great way to make friends and fellow geeks--in fact, I'd probably be strung up by this site's forum folk if I didn't include a shout-out to their work on the Folding@Home project. Click the jump to find out how you can get involved in this and other awesome distributed computing efforts. +10 Light Side points for you.