Switching web page languages - how?

Is there support to somehow automate the localization of web pages in
Rails? I need to create an application that must allow the user to
dynamically switch between several languages -- luckily, all of them
left-to-right languages.

Most guides and books do not even mention that issue and assume everyone
is using English. Are there any guides or documentation about how to
best do this?

Have a look at:
http://raa.ruby-lang.org/project/ruby-gettext/

Isak