How you keep your computer awake with jiggle

We've all been there: You're watching a video or running a slide deck, when suddenly the screen dims. Or you step away from the PC for an extended period and come back to find it
locked out or in standby mode.
Why does this happen? Because Windows hasn't
logged any mouse or keyboard activity, so its
power-saving settings kick in.
Sure, you could monkey around with Windows'
power settings, forcing the system to avoid
screen-dimming, standby, and other power-
saving modes -- but that's a hassle.

And if you
don't remember to undo those settings, your
laptop's battery life will tank.
Furthermore, some businesses don't allow
employees to alter their PCs' power-saving
settings, so you might be stuck with, say, a 30-
minute time-out. If only you could hire an intern
to jiggle the mouse every few minutes!
How about a software solution instead? Windows
may not be smart enough to know when there's a
movie playing or a projector connected, but at
least two utilities will simulate the actions needed
to keep the OS alert and active: Caffeine and
Mouse Jiggler.
True to its name, Caffeine is like coffee for your
computer. Every 59 seconds, it simulates the
press of the F15 key to keep your machine out of
screensaver/standby mode. F15? It's a key
recognized by Windows, but virtually nonexistent
on actual keyboards, and therefore not likely to be
assigned in any programs you use. In other
words, repeated F15 presses shouldn't mess with
anything you're doing. If it does, however, there's
a command-line option that will use the Shift key
instead.
(Note to Mac users: There's an eponymous
program for your OS , but from a different
developer.)
As for Mouse Jiggler, same deal -- but with your
cursor. Just run the tiny app as needed and click
Enable Jiggle. After a couple seconds, you'll see
your pointer start to, well, jiggle. If this has the
unwanted effect of making onscreen controls
appear (like in Windows Media Player), enable the
Zen Jiggle option, which does the "jiggling"
behind the scenes, with no actual cursor
movement.
Both utilities are free; Caffeine's developer accepts
donations. I find either one superior to messing
with power settings.