you can turn off BlackBerry camera shutter sound with BlackBerry CameraMuteApp on GSM devices.You launch it via the icon, then press Menu -> Add MenuItem then you go to your camera app.
Now when you want to mute the sound of the shutter you simply click Menu -> Mute! and after you have taken the fotos you click Menu -> Unmute! to turn on the sound again.
After each reboot you have to add the MenuItem to the Menu again.