If you install Crunchbang, it doesn't matter which language you choose during the installation, the default language after the installation is English, but you can easily customize the system to use your native language.
sudo aptitude install language-selector
Hit Alt+F2 and type gnome-language-selector
Now select the language you wish to use and apt will grab the appropriate packages for you
(machinebacon) The page describes how to change the standard language in an older release. The language-selector application is not in the repo's of Debian squeeze/wheezy, so the solution cannot be applied anymore. Marked [Obsolete]