Usually a red "L" on the command Dial - Flick it to this and this "locks" the camera. As far as im aware - This is the only way to "Switch it off" short of taking the batteries out
Yep - L is locked. The LED Display usually still shows the number of frames taken on the roll of film - just to let you know at a glance if you need to grab a spare film before going out with the camera.
There's a manual here for it, in case you didn't get one!
...JEMDNA finally gives a useful answer on the forums...