Raise your hand if this has happened to you: You're watching a movie on your laptop, when all of a sudden the screen goes dim. Or you're giving a PowerPoint presentation and your PC suddenly goes to sleep.
These hassles can happen after a period of "idleness," when the system detects no mouse or keyboard input. Blame Windows' power settings, which by default try to conserve power if they think you're not doing something. (Funny how Windows isn't yet smart enough to know if a movie's playing or there's a projector connected to your laptop.)
As you probably know, all it takes is an occasional jiggle of the mouse to keep the system humming. And that's the idea behind Mouse Jiggler, a free utility that "fakes" mouse input--and saves you from having to mess with Windows' power settings.
Just run this tiny app as needed--say, before you start your movie or presentation--and click Enable Jiggle. Then take your hands off the mouse for a couple seconds. You'll see your pointer start to hop back and forth a tiny bit--enough to trick Windows into stayin' alive.
In some programs (like Windows Media Player), mouse activity like this can have the unwanted effect of making onscreen controls appear. For situations like those, enable Zen Jiggle, which does the "jiggling" behind the scenes, with no actual cursor movement.
Note: This program is donationware. It is free to try, but the author accepts and encourages donations towards further development.