Caffeine

If you have problems with your PC locking or going to sleep, caffeine will keep it awake. It works by simulating a keypress once every 59 seconds, so your machine thinks you're still working at the keyboard, so won't lock the screen or activate the screensaver.

The icon is shown above - it's the leftmost one in the task tray, and this is all you see. Double-clicking the icon empties the coffee pot (that's what the icon is) and temporarily disables the program. Double-clicking it again refills the pot, and will keep your machine awake.

By default the app starts enabled, and works every 59 seconds. There are some command line switches you can use to alter this behaviour:

xx - where xx is a number which sets the number of seconds between simulated keypresses. This must be the first text on the commandline
-startoff - application starts disabled.
-exitafter:xx - application will terminate after xx minutes
-activefor:xx - application will become inactive after xx minutes
-inactivefor:xx - application will become active after xx minutes
-appexit - terminates current running instance of application
-appon - makes the current running instance of the application active
-appoff - makes the current running instance of the application inactive
-apptoggle - toggles the running state of the current running instance of the application
-replace - closes the current running instance, replacing it
-noicon - does not show a task tray icon
-useshift - simulate the shift key instead of F15
-showdlg - shows a dialog indicating whether caffeine is active