The NEC LCD2490WUXi is a high-end 24" IPS LCD. It's basically a 24" version of my 20" 20WMGX2 (which they don't make anymore, although you may still be able to find one). The 20" one is also available as the 20WGX2.
Main differences between the 20" and 24" are size (obviously), resolution (1920x1200 vs. 1680x1050, though you will need a pretty good video card to keep your framerate up in games) and speed (the 24" is just slightly slower).
I'd have bought the 24" version myself if it weren't for the fact that I didn't think my graphics hardware could keep up at 1920x1200 (C2D 2.13GHz, 7900GT) and the price, which is approximately double for the 24".