While I agree that turning the screwdriver into a magnet (though any tinkerer worth his/her salt would have already done that) can retrieve the screw, I think it would be far easier and faster to take a small piece of cheese from the sandwich, stick it on the end of the screwdriver, and snatch the screw from the depths of the distributor. Just like putting gum on the end of a stick, and without sacrificing the lamp…
Greg.