Screen saver programs, originally intended to help prevent damage to older computer monitors, are often used now for security or entertainment purposes when the computer is idle. Most operating systems include a few built-in screen savers that display animated geometric patterns or photos, but you do not have to go too far to find screen savers that educate as well.
Windows users still trying to get the hang of Microsoft Office 2010, for example, can grab a free screen saver that shows tips for using the software. A trial version of the Universal Tutor screen saver from Cool Educational Software is available; an annual subscription costs $30.
Recent versions of Mac OS X have included screen savers that display the Word of the Day from the New Oxford American Dictionary, or an RSS Visualizer that pulls down headlines from online news sources. To see what is available in your version of Mac OS X, click the System Preferences icon in the Dock, click on the Desktop and Screen Saver icon and click the Screen Saver tab in the box.
Plenty of shareware sites offer free screen savers, but be careful when installing any third-party program, as malicious software may also be along for the ride. Screen savers can also sap resources from the computer, so go to your computer's settings and just set your monitor to turn off after a short period of inactivity if you would rather not lose processing power. But if your computer has power to spare, donating its idle time to a group-computing effort like SETI@Home or one from the Boinc project usually gets you an interesting screen saver - while helping scientific causes.
