No, it doesn't show you pictures of Tribbles or Mickey Mouse, but it does dim your screen effectively. Some people insist that, due to advances in phosphor coating technology, today's displays don't have "burn-in" problems like the original Mac did. Regardless of whether this is true or not, dimming the screen also keeps your Mac from distracting you, keeps others from peering at work in progress, and reduces power consumption by about 23%, even for non Energy Star compliant monitors (see Byte Magazine, January 1994, page 204).
 
Setup
To turn on Sleeper's screen saver, simply turn on the "Screen Dimmer" checkbox in the control panel and enter the number of minutes of idle time you'd like Sleeper to wait before dimming the screen.
Sleeper allows you to put the mouse in one corner of the screen to dim immediately, and in another corner to prevent the screen from dimming even after you Mac has been idle longer than the dimmer delay time. The "Dim Now" and "Dim Never" buttons allow you to select these corners.
For the screen dimmer, "idle time" is defined as the amount of time since you last moved the mouse, typed on the keyboard, or inserted a disk.
Screen Dimmer Details
Note that if you have an Energy Star monitor, you should continue to use Apple's Monitor Energy Saver (or your manufacturer's equivalent) to turn off your monitor when you are away from your Mac for long periods. Sleeper cannot perform this function, but is useful for dimming the screen before the Monitor Energy Saver's minimum delay of 15 minutes takes effect. This capability will be built into a future release of Sleeper.
Sleeper works by changing the monitor's gamma table, which controls the brightness of the signals which drive the display. Doing this requires Color Quickdraw and GDevice support for your monitor(s), so Sleeper's screen dimming will not work on the "compact" Mac models (512, Plus, SE, SE/30, Classic). If you use Sleeper on one of these machines, it will not dim the screen, but the disk sleep feature will still work.
