You can use one of the virtual terminals instead logging into a desktop environment like kde or gnome. A desktop environment that is just a terminal is an oxymoron. There is no desktop environment in that case.
If you mean that you want to be able to launch gui apps, then simple use xinit. By default, if you don't include a client program, and don't have a ~/.xinitrc file, xinit will launch xterm. There is the terminal you are asking for!
xinit -- :0.0
You could try this out from where you are now. Press [CTRL]-ALT-F2 to switch to VT/2, and then enter:
xinit -- :1.0
which will start another x session on VT/8.
If you have a second monitor and aren't using it in your current session, you could run
xinit -- :0.1
You probably would want to start a window manager if you are going to run gui apps. It is possible to use Xorg options (e.g. -geometry, -offset, etc) so an application is displayed how you want, but to resize a window later, and for other things, you need a window manager.
Last edited by jschiwal; 03-12-2009 at 11:41 PM.