AFAIK, the only way to share a currently-running X app is to use the
"desktop sharing" feature of KDE 3.1 or greater. 

On Mon, 2 Jun 2003 ir0nkid@linuxjunkies.com wrote:

> >
> > X can display remotely on a program-by-program basis.  VNC requires that
> > you export the entire display, desktop and all.  Both can be tunnelled
> > via SSH.
> >
> 
> I have a similar question regarding the original post.  I also would like
> to be able to remotely control my X.  I know how to use X applications
> remotely by exporting the DISPLAY, or with ssh:
> 
> # ssh -X user@xapps
> 
> But that will only allow you to start a new app (say x-chat), and not the
> one that is sitting on my machine at home (unless i am missing something)
> 
> a friend of mine was trying to tell me to run >gdm &   or >xdm  and this
> should give me the destop manager login.  But what i would like to know is
> if i can somehow use my desktop that is currently logged in.  I played
> around for a bit trying to export the DISPLAY different ways (but i'm
> still kinda new to it).
> 
> I also tried out the vnc server that comes with tightvnc, and have gotten
> it to *kinda* give me a gnome destop (fonts are there) by modifying
> 
> ~/.vnc/xstartup
> 
> by making the last line
> 
> gnome-wm &
> 
> But all this appears to do is just start it's own X server (apposed to
> allowing me to use my account locally logged in.  Is there a way to do
> this, and i have goofed somewhere?  Any input is appreciated.
> 
> 
> thnx,
> 
> jacob
> 
>