I dunno. I've always done complex projects via command line tools. My general impression is that as complexity increases, it becomes increasingly impractical to have everything you need on the screen, anyway. Especially if you're trying to tile all the little windows.
This is why multi-head video cards were developed - if you don't have enough screen space, you need more resolution and/or more screens. I've got two monitors (side-by-side 22 inch LCDs - one with a portrait mode stand) on my current workstation here at home, but personally (if I had the space) I would love to have a triple-head system, with the main screen being a 42" LCD with the side screens being portrait-mode 22 inch LCDs; I just don't have the desktop room (but I might get another 22 inch; I do have room for a third one of those).
I've found that have multiple monitors, coupled with virtual desktops, to be invaluable when coding (admittedly, more so for web development; you can have one screen with your IDE and/or FTP session, and the other with your browser(s) - mod, push, test, ad-infintum).