Simplicity living rule #8. One may be the loneliest number, but there's no easier philosophy to follow than this: Keep the things you own (especially technology) down to only one. Listening to music? One iPod. One speaker set. If you have two, only get rid of it by selling or donating. Hold on to that one item for as long as possible.
For me, I follow a similar philosophy with living room and office furniture as well. Primarily because of lack of space, but I also feel keeping things limited to one item, whether that be an office chair, 3-seater sofa, or media shelf, simply makes decision-making much easier when I need to do something. Even if it's just putting toast in the oven.
Scientifically speaking, there has been evidence that reduction of allocated resources or devices allows for clearer decision-making. Similarly, in CSCW (computer supported collaborative workspaces), the idea of space and place plays a great role in increasing efficiency of the people who work in them.
Although I personally don't know many people who have more than a single space for entertainment in their homes (well, TV's may be a different story), I think it's always good to keep in mind how much waste is generated everyday and how great one can curb our consumption, even if it starts with one person - yourself.