ubuntu keyboard memo

I'm using Ubuntu 9.04 Netbook remix. Today I failed to recover my keymap settings after I mistakenly set the language environment (set-language-env) to one of Catalan. The key didn't hit the right character that was on a key. I tried (Ubuntu menu) -> System -> Preferences -> Keyboard, but nothing changed even after I hit the button "Apply System-wide...".

Then, the following line worked like a magic:

$ setxkbmap

I found this command while playing with Shell searching for set-* commands with [tab] key.