from what i can tell, that extension basically just changes the default country/language for pages that are designed with autodetecting multi-language versions, as well as changing spell-check dictionary. it might also switch the language of menus and dialogs in firefox as well?
"The two seater is being joined in a few weeks by a larger two-plus-two model with a rear seat for munchkins." ~Jim Mateja, Chicago Tribune, in regards to the Z32.
Andrew Janeshek // jnshk@aol.com // 1992 NA 2+2 [Stage 2-ish]