It seems that the norm for development systems has been a multiple screen approach for a few years. I have currently come to challenge that view thinking that one screen can suffice if the resolution is good and the aspect ratio is wide, say, 16 by 9.
I have a particularly interesting development setup requirement which implies that I use both a PC and a Mac simultaneously. Until a few days ago this implied rolling my chair from one end of the desk to the other and physically switching machines.
I tried a remote desktop approach which was ok but not as responsive as I had hoped due partly to the wireless network. Finally, I found a TrendNet keyboard, mouse and video switcher that seems to have done the trick.
So, my setup which I have begun to develop for Windows Phone 7, android and iPhone / iPad has a wide ratio LG screen, a Mac Mini, a quad core PC, a single keyboard and mouse and removes the need to scoot up and down the office on my wheelie chair to get to the other keyboard. It has the other advantage that my Mac Mini detected the fact that that stylishly White yet, to me, esoteric Apple keyboard, which is unwell since I poured tea into it anyway, has been replaced by a single ergonomic Microsoft 104 key keyboard that I am more used to working on and hence more productive.
My only problem was the fact that the LG screen only has a single audio input so my solution to that was to connect the Mac to the screen and the PC to the line-in of the Mac and to use this free LineIn program to retransmit the PC sound to the screen speakers.
So now, a simple click of the button on the KVM unit switches from Mac to PC and back all on the same keyboard and mouse. An added bonus is that I am now saving the cost of running two other screens which is going to be a bonus when my 100% off-grid power generation system comes on line in the fullness of time.