It's an old thing screen savers, but really, there so entertaining who wants to get rid of them??
Older monitors from the 80's through to the mid 90's needed screensavers to prevent burn-in. Thats where the electron guns in the back of the tub are continuesly being fired at the same spot (take the windows start button as an example) and eventually degrade the coating that produces the coloured light over that particular area. Screensavers gave the monitor a 'tea break' when the computer was not is use, and the chances of burn-in was reduced, or took longer to occur.
In modern half-decent monitors (say, turn of the century) screensavers are not needed. The coatings are much less degradable. In tft's this is not an issue at all and screensavers are not needed.
Tft's however have another problem, it has been noted that eventually the blacklight (due to the way the light is created) degrades over time. So instead of a screensaver for a TFT monitor, you better setting it go on standby.
Hope that helps.
