Hi Jayfram
You could configure the computer to stay on:
apple menu, system preferences, energy saver, power adapter tab
set computer to sleep never
display sleep to never
uncheck automatically reduce brightness before display goes to sleep
this will allow your computer to stay on while it's plugged in.
The advantage of the screen saver is you can password protect the computer. this way no one can stop the slide show; and start messing around with your computer. The down side is people can still disrupt the slide show by accidentally bumping into the computer; but after a bit it will resume again.
If you want to use the screen saver:
apple menu system preferences, security, check require password x minutes after sleep or screen saver begins. in this case you might want to set the computer to require password quickly.
You may also want to make it easy to quickly enable the screen saver:
apple menu, system preferences, desktop & screen saver tab, hot corners button, set a hot corner.
while your there you can of corse configure the setting for the screen saver slide show.
If you chose to do an iphoto slide show. bumping the mouse wouldn't stop the slide show. iPhoto gives better control over slide shows. but you can't lock the computer like you can with a screen saver.
