multiple X servers on one computer?

[Anand Buddhdev <arb anand org>]

Is there a way to run more than one X server on my linux system, so that
I have one instance displayed on ALT-F7, the next on ALT-F8, and perhaps
a third attached to a VNCserver so that someone can use my computer
remotely, complete with his own desktop and settings simultaneously?

I am particularly interested in the VNCserver option, because I want
to try and device a system where a large number of users can all use a
single linux server with VNC for example.

-- 
Anand Buddhdev