My primary workstation has dual 19" Samsung flatscreens. They are not widescreen. I really like that setup, especially in conjunction with RDC (remote desktop). They have really thin bezels all around and they work great butted up against each other. I primarily use the right screen for one or more, fullscreen RDC windows for other computers. Most of my work is done in the left screen. I rarely stretch a window across monitors (maybe because the separation of the screens makes that awkward). My taskbar is attached to the right side of my left screen which puts it right in the middle of my workspace. I like it vertical because I can see so much more on it than when it's horizontally across the bottom.
I really like and am really used to my setup. That is until I ran across this blog post by Scott Hanselman, which shows the use of 3 huge monitors to make a single workspace. I'm jealous!
He says they run the center, 30" widescreen at 2560x1600 pixels with the 22" widescreens on the sides running at 1050 pixels wide. That's a total of 4660 pixels across the screens. It would be cool to see a shot of this with actual programs running.