michaelsanford
Translator, Web Developer
My system is localized in French, but I've never noticed this happen in the terminal before! None of the other commands do this (as far as I've checked, like mkdir, awk, etc), and all the manpages are English.. 
Cool!
Code:
[gwailo:~/Library/Preferences]% grep
Usage: grep [OPTION]... PATRON [FICHIER]...
Pour en savoir davantage, faites: `grep --help'.Cool!