This is guaranteed not to be a stupid (or even a funny!) joke; and it's guaranteed to be a worthy cause and it's guaranteed to be real (not an Internet urban legend like warnings of the Good Times Virus)...
In case you haven't heard about this (or did but don't know the URL) - a project is underway to get ordinary people with computers and an Internet connection to help on the SETI (Search for Extra-Terrestrial Intelligence) Project. You know - just like Jody Foster in the movie Contact! A satellite in Puerto Rico has captured radio waves and they need computers to analyze the data for signs of intelligence via radio transmissions.
Unless you have a REALLY fast computer - you will set it up as a screen saver - so it will only kick in when you're not using your computer. When it's done calculating - it will connect to the Internet, upload the results and download new data for your machine to analyze. The analysis is quite time-consuming. On my 300 MHz Machine it took 73 hours 35 minutes to complete a unit of work. There are version for both Windows and Macs (and Unix and Linux and a bunch of others).
Anyway - unless you REALLY need a cool snazzy looking Screen saver that you paid a lot of bucks for - you can participate in an exciting research project at no cost to you. If you use your computer a lot like I do - it's really better just to leave it on all the time (newer machines have power saving features such as shutting your C Drive down for example) and this will really help the project as it will run while you are doing things like sleeping or are at work...
To Download and get more info check out
http://setiathome.ssl.berkeley.edu
Danny Sniderman