If fiddling with a dimmer switch isn't an exacting enough science for you when it comes to tweaking the lighting in a room, Junji Kawabe designed his light=weight lamp to be controlled by gravity. So the heavier an object you place on its scale, the brighter it shines.
So with a set of calibrated weights, you anal types can in theory dial in the exact amount of light you want. Need it a little softer for ambient mood lighting? Just take off a gram or two. Need a little more glow for eating dinner? Just toss a few more pounds on there. Who knows, with an elephant or two, you might even be able to create your own miniature private sun.