Picture: http://chir.ag/stuff/5lcd.jpg
* LCD1: Communication (chat/im, email)
* LCD2: Test browsers (IE, FF, Opera, Safari), Photo Editor
* LCD3: Main browser (Chrome)
* LCD4: Text Editor (EmEditor), SFTP
* LCD5: Media (music, video, audio controls)
I'm about twice as more productive on this setup than on my laptop.
A 30" monitor is bigger than 4 1024x768 monitors, remember.
(Why don't I like multiple monitors? They take up too much space, and it's very hard to get one monitor adjusted to be comfortable... much less 5 of them. And, pressing a key to switch to a new display is not much slower than glancing in another direction, unless you aren't planning on interacting with what you are looking at.)
Even a 9" monitor is good enough with Xmonad.
Maybe you need two monitors if you are not an Xmonad/keyboard power user... but otherwise, two monitors just gets you extra neck strain.
Two monitors comes into its own when you need to see more information on the screen at once. In my IDE as it is, when e.g. debugging, I have loads of tiled information displays, between the source, disassembly, CPU and FPU registers, CPU stack, memory, symbolic call stack, watches, locals, loaded modules, breakpoint list, thread list, log, project layout, etc. Fitting all that into 9" would be unreasonable; add in the actual running program in a terminal window, and scanning logs of previous runs in less, and it's hard to get by without two screens.
It doesn't sound like the most ergonomic setup, but it must work for you since you say you're twice as productive!
I don't do that. My arms/mouse/keyboard face the center LCD and I type/click without looking down. I turn my head slightly if needed but mostly it's enough to just turn my eyes. Like I said, sitting back helps.
Do you not feel the need for a marker board of some kind though? As in, what if you need to sketch something out?