Anyway, in our NOC we current have two LCD projectors displaying outputs from two different computers. On one of the display's, I would like to be able to take 4 VGA outputs from 4 workstations, and display it on the screen (aka: Hollywood square style).
This kind of problem is normally solved using software. If the applications driving the 4 VGA displays are all using X-Windows, then try an X Window manager that supports capturing a window and displaying it in miniature form in a dashboard or button bar. It should be possible to adapt this easily to display the 4 applications in a 2 x 2 matrix. If the applications driving the displays are not using X-Windows then it should still be possible to build an X based solution but you would have to start by using VNC on the application machines to provide a remote viewer that can display window contents on the X machine. Chances are you already have people with the skills to do this whose time is not fully occupied in their day job. If so, the marginal cost could be close to zero. --Michael Dillon