In Andy Hunt’s presentation at NFJS, he mentioned the benefits of having a “dual monitor” setup. According to this NY Times article, you can be 20-30% more productive. The reason being is you are not context switching (not directly in the article more in the presentation). By switching programs or hunting for the one you are looking for on a small screen, it can reduce productive drastically - this is context switching. Context switching isn’t just finding programs on the screen. It is answering the IM or the email you just received. It removes your concentration from what you were currently working on and this really hurts productivity.
Now, if I can just convince my wife I need a pair of 30” displays.