VNCServer

Install vncserver (as root) in Debian
This package provides a vncserver to which X clients can connect and the server generates a display that can be viewed with a vncviewer
It contains an X server connector so clients can connect to your local X desktop directly.
Note: This server does not need a display. You need a vncviewer to see something. This viewer may also be on a computer running other operating systems.
<code>apt-get install vncserver</code>
Choose your desired window size and color depth, then, as an ordinary user, open a terminal and type:

#vncserver -geometry 1024×768 -depth 24
This will prompt you to create a password:
You will require a password to access your desktops.
Password:
Verify:
This will save a scrambled password in the file ~/.vnc/passwd.
Once that’s been done you can create a new server by invoking

#vncserver

This will start a new server and show you the “desktop” it is running upon. This is something that you’ll need to know when connecting to the server.
 
The server will start and tell you where to access it
desktop is debiantest:1

Here is an example of my setup of vncserver and I have started 2 instances of vncserver.

Connecting to VNC Server
I am using windows xp client to connect to debian server (where vnc server is running) for this you need to download vnc viewer.There are many VNC viewers i am using tight vnc viewer downloaded and install from here
You need to have port 5900 and 5901 open on your router for the so you can access the server through VNC. 
Open the VNC viewer on your remote machine, enter the IP of your Debian server.

Enter the password you gave for the vncserver setup.

Now you remote login into your server with x11 features. You can configure your server from any computer in the world.