I noticed that this week's Office Depot had this 19 inch widescreen monitor $50 off for a final price of $299. With a resolution of 1440x900 and DVI input, it seems nice. Obviously, it's not got the resolution of the Apple 20 inch (1680x1050), but you can have two with money left over.
http://www.xerox-displays.com/widescreen.html
http://www.xerox-displays.com/widescreen.html