I wanted to have an option in my program, which prevents the screen from turning off. I've found sceKernelPowerTick() should do the trick, but as the parameter is undocumented, I've been wondering how to re-enable the turn-off?
IIRC the parameter should always be 0. If you want to "re-enable" the turning-off then just stop calling the powerTick (you have to call it periodicaly to stop turning-off).