Hi, All
The QPE/System", "setBacklight(int)" does not work on tosa, so as i am lazy, and didnt want to look into opie/qtopia/qt code, i've modified applete from here to do the changes through procfs http://zefamily.org/ZaurusProjects.html.
I'm not a c++ programmer, so all that QT stuff makes me dizzy a little, but anyway it is working and does what i need:
http://www.gfdsa.org/~gfdsa/liblightswitch-tosa.so.1.0.0
http://www.gfdsa.org/~gfdsa/lightswitchapplet-tosa.cpp
lightswitchapplet-tosa.cpp
compiled for OZ/3.5.2

Any comments are welcome

Nice. Note that brightness control in Opie has been fixed to work with Tosa some months ago in CVS. It will be part of OZ 3.5.3 due pretty soon.