How to boot Ubuntu in console mode (no X)

Despite the fact that graphical user interface is easier to daily work, I really prefer command line interface.

I tried to disable graphical startup on Ubuntu by editing inittab file, but what a surprise when I did not find it.

Where is it? After some googling I found out that to always boot in console mode you must execute this command:

sudo update-rc.d -f gdm remove

Every time you wish you can invoke Gnome from command line by typing

startx <ENTER>