Just swapped over at work from a single Dell 200FP 20 inch flat panel to dual Dell 1800FP 18 inch flat panels. Either setup is, in my opinion, a very nice. The 20 inch was bought at the end of last year when Dell was having a special that brought the price down to about $800, the current price is pretty outrageous. At that time the developers had the choice of dual 18 or single 20. I, and one other person, chose single 20, the others went for dual 18. The 2000FP is a very nice monitor, but dual 1800FP turns out to be better. Recent reorgs and moves means I can now pinch, or "free up", enough 1800FPs for me.

The dual setup has a lot more useful real estate because its greater horizontal space is more useful to me that the greater vertical with the 20 inch monitor. It let's me keep IntelliJ open on one screen and still let's me see a browser or running app on the other. Setting up the linux box wasn't too difficult. As it's a Nvidia card I had to download and install their driver before the dual head feature would work. For the rest of it I just copied a colleague's XF86Config.