root@ubuntu:~# apt-get install vnc4server

root@ubuntu:~# su - takeshi
 takeshi@ubuntu:~$
 takeshi@ubuntu:~$ vncpasswd
 Password:
 Verify:

takeshi@ubuntu:~$ vncserver :1
 New 'ubuntu.tk.net:1 (takeshi)' desktop is ubuntu.tk.net:1
 Starting applications specified in /home/takeshi/.vnc/xstartup
 Log file is /home/takeshi/.vnc/ubuntu.tk.net:1.log

takeshi@ubuntu:~$ vncserver -kill :1
 Killing Xvnc4 process ID 14754

takeshi@ubuntu:~$ tail .vnc/xstartup
 # unset SESSION_MANAGER
 # exec /etc/X11/xinit/xinitrc
 [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
 [ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
 xsetroot -solid grey
 vncconfig -iconic &
 x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
 x-window-manager &
 exec gnome-session &

takeshi@ubuntu:~$ vncserver :1 -geometry 800x600 -depth 24