There is a vnc module for X that can be installed which will provide the native :0 X display when connecting remotely with the vncviewer.
1. On Ubuntu, install the "vnc4server" package (universe). This will provide "/usr/lib/xorg/modules/extensions/libvnc.so" (The vnc.so module for VNC 4.1.2 was changed from vnc.so to libvnc.so.)
2. Add "vnc" to the Module section in /etc/X11/xorg.conf
Section "Module"
...
Load "vnc"
EndSection
3.a.If your VNC server is running in a secure environment, you can disable authentication with the following configuration:
Section "Screen"
...
Option "SecurityTypes" "None"
EndSection
3.b. If your VNC server is NOT running in a secure environment, you will need to set a VNC password using the vncpasswd program:
# vncpasswd
Password:
Verify:
Then tell the VNC module where the password is stored in xorg.conf:
Section "Screen"
...
Option "SecurityTypes" "VncAuth"
Option "UserPasswdVerifier" "VncAuth"
Option "PasswordFile" "/root/.vnc/passwd"
EndSection
4. Logout and restart X (Ctrl-Alt Backspace)
References:
<http://www.realvnc.com/products/free/4.1/x0.html>;
<http://gentoo-wiki.com/HOWTO_Use_TightVNC_W/_JPEG_Compression_to_connect_to_existing_X_Sessions>;