At work I recently got bequethed a 20" widescreen LCD. I'm a big fan of the Dell LCD monitors, crisp, feature rich (dual inputs on 17", QUAD input on 20"). In fact, the 2005FPW got great review, and uses the same lcd panel as the Apple Monitor. If you can pick one up on sale for as little as $380, I highly recommend it.
However, after setting it up and beginning to use it, I'm actually posed with the question: "Can a monitor be too big?" The answer is a decidedly... probably. I just moved up from a 17" to this widescreen monstrosity. I am actually at a loss for my data and I feel that I have to swivel my neck to take in the whole screen.
Another thing: Firefox under windows doesn't seem to play well with the ultra-wide resolution. I'm currently running at the LCD native 1680x1050. When I have the Firefox window in the far-right of the screen and bring down a menu, the url history or anything the responding menu appears about 1/3 way in from the right-edge of the screen. I think it's drawing methods must be 'confused'.
"Too big"? maybe not. "Absurdely huge"? definitely.