Test version is available...OTA install from your blackberry browser:
http://www.tateu.net/software/bb.php?f=bblight
If you are installing over an old version, you will need to reboot.
To use:
Navigate to the BBLight Icon and run the program.
To have the program launch automatically every time your blackberry turns on, select "Activate on Startup."
Poll interval is how often the program checks to see if it should keep the backlight "Always On." Set this to something less than your device's backlight timeout. My device's backlight timeout is 30 seconds, so I set the Poll Interval to 24000 (milliseconds).
To keep the backlight "Always On When" ... check the appropriate box (Active, Out of Holster, or External Power/Charging).
To have the backlight turn on when an SMS or email is received, check the appropriate box.
To have the backlight turn on at a specific time of day, check the appropriate box, set the time and duration that the backlight should stay on.
Once you are done setting the options, press the menu key and choose "Save." This should save your options and activate BBLight.
If you want BBlight to be actively running, make sure it says "Active" at the top and press the menu key and choose "Close." This will leave BBlight running in the background.
If you want to turn BBlight off, press the menu button and choose "Exit." This closes all monitoring functions and exits BBLight.
UPDATE to Instructions:
And the first time that BBLight tries to turn on your backlight you will receive a notification from your device that BBLight is trying to change system settings (turning on the light). In order for BBLight to function, you have to allow this. Choose "do not ask again" and press Yes to allow. The message will appear twice. Allow it for both. I would recommend that the first time you run BBlight, turn on the "Out of Holster" option, then choose "Save" from the menu. This should immediately bring up the change system settings notification. Once that is done, you can turn off the "Out of Holster" option and save the settings again.