How to access the terminal in Ubuntu GUI without a mouse

I have an embedded Ubuntu 12.04 system running with no monitor and I need to run a command in the terminal. I can connect a USB keyboard (or even a mouse, but a mouse would be difficult to use without a monitor) and log into the Ubuntu desktop. How can I bring up the terminal using only the keyboard without any visual feedback?

Just hit Ctrl+Alt+F1 to switch to another tty. That's probably easiest.

For Unity (shipped by default since the Ubuntu12), Gnome, LXDE, Cinnamon and MATE, the Ctrl+Alt+T keyboard shortcut will work if you are already logged in.

If you are using Xfce (Xubuntu), however, it would be Super+T. (Note that Super is the Windows key)

And as far as I am aware, in KDE, while it is also Ctrl+Alt+T, for some reason, there are issues with the default shortcuts. So you have a few other options. Press Alt+F2, then type konsole and press Enter. If you have full access to the system, and you want to set up a keyboard shortcut, right click on the Menu, find Konsole, select Advanced tab, Current shortcut key. Select a combination of your liking, though be careful with shortcuts already in use.

As per Terdon's request, this answer has been expanded to provide information about the different Ubuntu environments.

If you still have access to it, ALT + F2 is essentially a one-time run dialog. It can be re-enabled in System > Preferences > Keyboard Shortcuts.

This used to be a standard short cut. Why Canonical removed it, I'll never know.

http://help.ubuntu.com/community/KeyboardShortcuts