How to change locale in ubuntu linux?

Here: http://blog.andrewbeacock.com/2007/01/how-to-change-your-default-locale-on.html
http://tlug.dnho.net/?q=node/237

Nos comentários achei esta dica:
I love that everytime I had a problem with my computer, someone else has already solved, haha.

My two cents are that, as far as Ubuntu Hardy, I also needed to change

/etc/default/locale