It would be useful, if you could temporarily turn of the Backlight time-out feature. For example, showing some pictures to other people. When you lent the n900 to other people, it usually happens that the screen turns off automatically to power save mode. If the hw-keyboard is closed, you usually need to give some extra instructions how to get the screen light up.

Proposal:
Hold down the lock switch slide for 5 sec and the backlight time-out will turn off (a small vibration would be a good indicator of this to activate).

Use lock switch again to deactivate this feature and turn the backlight off.

It might be a good idea to add an extra vibration info after about 5min if you have forget to turn of this "ForceLight" feature. ( something like in lens-cover-reminder http://talk.maemo.org/showthread.php...cover-reminder )

Br, Spude