Occasionally Ubuntu 12.04 64-bit on my Panasonic CF-51 laptop will freeze up. The mouse cursor can still be moved, but I cannot access anything and no shortcut keys seem to work. Is there any way to access the terminal when this happens?
SnapOverflow
You may be able to access the command line only interface by pressing Ctrl + Alt + F1 and then typing your short username (it has no spaces, is all lowercase) and password to login. Then you have a full screen terminal that is not dependent on the GUI.
You may be able to restart the graphical interface by pressing Alt + Sysrq + R and then Alt + Sysrq + K. Be forewarned though that will log out any graphical sessions so you will loose any unsaved work in the GUI, etc.
You can access the terminal with Ctrl + Alt + F1 through F12. This is called a "tty" terminal. "tty" stands for "teletype". The keyboard shortcut will not get you to a terminal, but to a login prompt. Once you log in with your normal user name and password (which will not appear), you will then be taken to a bash prompt.