Localization

As I read here,
http://www.postgresql.org/docs/8.1/interactive/charset.html

once you install your postgeSQL system, you cant change your behavior of
order by statements?
Does that mean that there is no way to order in one database by English,
in another by Russian, and on third, Macedonian.

And what about different tables in a database?

And in a single table but different column?

I have read a bit about nls_string function but it is not recognized by
postgresql at least in my installation.