S60 Applications

S60SpotOn keeps your display backlight permanently on.

If your smartphone (e.g. Nokia N80, N90) supports a camera-flash, you will be able to turn it on/off too (torch; since v0.04).

This application is freeware

Lights On is a software service which is able to automatically turn on and keep activated the screen light of the phone as long as the charger is plugged in or based on a timeout period

The screenlight will never turn off until either the charger is plugged out or the timeout expires. It will also try to keep the keypad unlocked if you set this. You can also manually turn the light on/off using the applications settings.